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A weekly discussion of what’s new and interesting in astronomy with Dr. Derrick Pitts

Last Build Date: Thu, 26 Apr 2018 21:19:36 -0400


On the Prowl for Solar Siblings Sun Shines in High-Energy X-rays

Tue, 24 Apr 2018 15:39:31 +0000

Our sun, like so many others, was born as part of a cluster of stars. Sibling stars have the same chemical composition and can be discovered by analysis of each star’s stellar spectrum. The problem? Dynamics of galactic motion have pulled the sibling stars all throughout the galaxy, far from their original positions. A new survey has looked at 340,000 stars to better understand the evolution of our galaxy’s stars. The Galactic Archaeology Survey uses a spectrograph on a telescope in Australia and a specially designed computer code to study the spectra of 340,000 stars in our galaxy.

A new analysis of an asteroid fragment found in the Nubian Desert, Sudan in 2008 reveals inclusions inside tiny diamond crystals. The environment where the inclusions were formed could only be found at the core of either a very large asteroid or a planet somewhere around the size of Mercury or Mars.

The Transiting Exoplanet Survey Telescope (TESS) was launched last week on a two-year mission to search for planets orbiting nearby stars. Kepler searched more distant regions and turned up more than 3,700 confirmed hits. TESS is expected to double that number. The method of discovery is transit – watching for regular periodic brightness changes in stars that might be attributed to orbiting planets.

Venus beautiful in the evening sky now; Jupiter up by midnight. Saturn and Mars hold down the pre-dawn sky but are losing to encroaching sunrise. Get up earlier to see them!

Media Files:

Shedding Light on Dark Matter

Tue, 17 Apr 2018 13:57:28 +0000

Scientists at the University of Washington have developed the tech to ‘see’ what could be a low-mass particle responsible for dark matter – the axion. They believe that incoming axions passing through a strong magnetic field could convert into radio waves. They are looking for particles with masses less than a billionth that of an electron. This years’ Franklin Awards Physics laureate, Helen Quinn, first suggested the idea of this new particle in 1977 with her colleague Roberto Peccei.

The premiere event of the Philadelphia Science Festival takes place this Friday evening.
25 locations around the region, mostly in inner-city neighborhoods, will host amateur astronomers with telescopes to show the wonders of the night sky. Two hundred partner agencies have put together nine days of over 80 events, plus the Science Carnival on the Parkway on 4/28 with over 180 exhibits and demos. Most of the programs are free and family-friendly, including the carnival.

Planets to be seen this week –
Evening – Venus in the west visible not long after sunset, Jupiter in the east by 10 p.m.;
Pre-dawn Saturn and Mars – high in the south at 5a, catching sunlight by 5:30 a.m.

Media Files:

Does Dark Matter Matter? st-th

Mon, 09 Apr 2018 15:21:22 +0000

Astronomers have detected a galaxy that seems to be devoid of dark matter. That possibility has theorists re-evaluating gravity’s role in keeping a galaxy intact.
A Columbia University-led team of astrophysicists has completed a study suggesting the presence of as many as 10,000 very small, low-energy black holes near the core of our galaxy. The mini-black holes have never been detected before because instrumentation has always been tuned to see the more energetic variety of black holes.
Dark sky highlights this week:
Planets; Jupiter in the east after 10 p.m., Saturn, Mars in the south, pre-dawn with Jupiter in the west about to set.
Notable stars: Sirius: brightest in our sky, Arcturus: 4th brightest in our sky, and Betelgeuse: 9th brightest star, a red supergiant; if it were centered here, it would extend beyond Earth (and Mars).

Media Files:

Phillyhenge st-th

Mon, 02 Apr 2018 14:21:25 +0000

Move over Stonehenge – Philadelphia will feature its own version on Friday, April 6 at 7:30 p.m., when the sunset will align with Market Street. This phenomenon happens a few times a year.

A planet 75% the size of Jupiter has been discovered, orbiting a brown dwarf star 46 times the mass of our planet Jupiter. This is of interest because brown dwarfs are the most numerous type of stars: low fusion temperatures render them not very luminous and they are often overlooked as ‘stars.’ For them to have planets significantly increases the possible number of planets in a galaxy and provides more context for the stellar/planetary genesis story.

This is a great week to gaze aloft and spot the Spring Constellations – 10p – West: Taurus, Orion, Gemini; South: Leo in the Keystone, Big Dipper above; East: Orange Arcturus, Hercules

Media Files:

How Big is Big? NGC_4414_NASA-med

Mon, 26 Mar 2018 20:44:51 +0000

An acceptable range for the estimated number of galaxies in the universe is between 100 and 200 billion, according to astronomer Mario Livio.

The Hubble Space Telescope’s successor has suffered another 5-8 month delay. The Webb Space telescope has entered the final phases of testing, but delays caused by integration difficulties have pushed back the launch date. The complicated folding of the sunshield is the culprit, and there’s 8 billion dollars on the line.

Media Files:

Serious Signs of Water on Ceres st-th

Tue, 20 Mar 2018 14:47:16 +0000

The Dwarf planet Ceres is showing signs of cryoactivity and…water(ice)! Sodium carbonate, a mineral seen by the Dawn spacecraft in orbit around Ceres since 2015, shows up on Ceres as a hydrated variety, indicating that water is bound to the mineral. Images show the presence of slushy cryo-volcanic eruptions.
Data suggests that ice is frozen into the soils on Ceres and there could be briny water layers just beneath the surface. The water can’t last long on the surface – there’s no atmosphere and radiation breaks the molecular bonds, so it evaporates quickly. That there is growth of the ice walls and cryo-volcanoes indicates replenishment must come from subterranean sources. Could it be an active water cycle of some sort?

Jupiter’s Iconic ‘Great Red Spot’ is no more. Now it’s the ‘Great Orange Spot.’ Color changes have been noticed since the earliest close flybys of Jupiter in 1979.

Skywatching this week – Evening: Venus and Mercury – 7:30 – 8 p.m. every night Venus rises higher, Mercury sinks lower. Pre-dawn sky from 5:45 to 6:15 a.m., every day Mars creeps closer to Saturn; watch as Earth overtakes the two planets!

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Dark matter’s impact on Andromeda’s size andromeda-th

Mon, 12 Mar 2018 15:03:51 +0000

Textbooks typically describe the nearby Andromeda galaxy as being three to four times larger than our galaxy, the Milky Way. However, newer measurements indicate that the two are actually on par. The discrepancy? Andromeda has fewer stars than originally estimated but more “dark matter.”
Astronomers actually now believe that what we see of Andromeda is only 10% of its actual mass.
Astronomer Vera Rubin realized the existence of dark matter in the 1970s when she tried to figure out why Andromeda’s motion didn’t match its estimated mass.
Andromeda and the Milky Way are on a collision course, and their relative masses will make a difference in how the collision will affect the stars, planets, and other masses.

The sunset this week comes after 7:00pm and we’re gaining about 2 minutes and 40 seconds of daylight every day through the end of April, when the rate begins to slow. Meanwhile, sunrises are coming earlier.

Birth Anniversaries this week:
Giovanni Schapiarelli, 1835 – canals on Mars;
Albert Einstein, 1879 – general relativity, special relativity;
Astronaut Gene Cernan, 1934, the same year the Franklin Institute opened its doors at its current location.

Media Files:

Spring Ahead skytalk-th

Tue, 06 Mar 2018 16:02:38 +0000

Remember to advance your timepieces one hour before retiring Saturday night; Daylight Savings Time starts Sunday morning at 2:00 am.

Dr. Pitts has returned from a visit to Mt. Wilson and Carnegie offices in Pasadena, California. In the 1920s, Edmund Hubble collected spectroscopic data on galaxies there, showing that they were moving away from the Milky Way. As the distances to galaxies increased, the faster they seemed to be moving.
Since then, we’ve come to understand that the increasing recessional velocity of galaxies (as was suggested by Einstein) actually is caused by the expansion of the universe pulling everything apart.

Hubble also figured out a rate of expansion, now called the Hubble Constant, that tells us about the early state of the universe.

Media Files:

Rover Still Rovin’ Rolling Ripple

Mon, 26 Feb 2018 16:12:14 +0000

NASA’s Mars Reconnaissance Orbiter has returned images that clearly show thick layers of water ice just beneath the surface and extending up to 100 meters down in some places. The layers were spotted on exposed cliff faces mostly in the southern hemisphere. Geologists surmise that the ice formed from thin layers of surface frost and snow that later compacted and recrystallized. As the cliff faces are exposed, the water ice sublimates and the dehydrated rocky material crumbles away and falls to the cliff footings, exposing new deposits of previously buried ice. That water is frozen into the Martian soil isn’t news. In 2008, the Phoenix lander scraped the soil surface not far from the Martian north pole and exposed layers of permafrost just centimeters below. Radar scans from orbit also indicate huge glaciers of ice are just 20 m below the surface and cover a third of the Martian surface.

Opportunity Rover has been operating successfully on Mars for 5,000 days – 13.5 years! Originally, the expected mission length was 9 months. It’s covered 28 miles and returned 225,000 pictures. It’s seen it share of dangers; sand traps, steep crater slopes, dust storms, cold, dim Martian winters, equipment failures, and communications issues. Engineers have finessed ways around all of these to send back information extraordinary information and images.

Media Files:

International Space Station Grounded? st-th

Tue, 20 Feb 2018 16:23:34 +0000

The Trump administration’s NASA budget proposal for 2019 recommends $19.9 billion dollars, which is $370 million above last year. However, the plan cuts out funding for International Space Station by 2025, as well as for the Office of Education. Dave and Dr. Pitts discuss the implications.

There is a panoply of planets in the pre-dawn sky; Saturn, Mars, Jupiter. In the evening: Venus is very bright but low in the West-Southwest.

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Planets, Planets A-Plenty Interacting Group of Galaxies Known as Stephan's Quintet

Wed, 14 Feb 2018 16:42:11 +0000

Planets have been observed for the first time orbiting stars in a distant galaxy 3.8 billion light years away. Einstein suggested that this form of detection might be possible.

At The Franklin Institute, the monthly Night Sky Observatory program featured author Richard Paul, who with Steven Moss wrote the book, “We Could Not Fail: The First African-Americans in the Space Program,” a nuanced description of the early history of NASA and the deep involvement of people of color. NASA was one of the first government agencies to change its hiring practices in an effort to ensure the success of the American space program.

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Countdown to the Super Bowl, and the Super Moon! st-th

Mon, 29 Jan 2018 16:26:03 +0000

On Wednesday, January 31st, don’t miss the Super Blue Blood Total Lunar Eclipse Moon! This lunar event means that the second full moon in a calendar month coincides with a lunar eclipse, and that the full moon appears slightly larger than usual. A moon like this one has not appeared in the sky since 1982.

Superbowl Sunday is also the 112th birth anniversary of Clyde Tombaugh, discoverer of Pluto.

Media Files:

Forecast Calls for Dust Moon - North Pole

Mon, 22 Jan 2018 17:06:08 +0000

Continue your lunation observations: The first quarter moon is on Wednesday Jan. 24. Here’s what to look for:

a. The line that separates the illuminated half from the not-so illuminated half is called the “terminator.”

b. Craters- the record of early solar system bombardment. The Moon absorbed a lot of what could’ve rained down on Earth.

Space material still rains down even on Earth – 100 tons of space dust every day, 36,500 tons per year. Sounds like a lot, right? Well, not so much… it’s a minuscule amount in relation to the Earth itself.

Media Files:

Happy Birthday, Buzz! Apollo 11 LM Interior

Mon, 15 Jan 2018 05:51:48 +0000

Of the remaining cohort of Earthlings privileged to set foot on the moon, let’s extend 88th birthday greetings this week to Buzz Aldrin. As the Lunar Module Pilot on Apollo 11, he was one of the first two humans to land on the Moon, and the second person to walk on it, in July of 1969.

On January 15th, 1973, the Soviet Union launched their second lander and rover to the moon, just a month after the final Apollo lunar mission returned.
Lunokhod 2 spent 3 months traversing, testing, and photographing. It fell into a crater in May 1973 and the mission was over. Interestingly, Richard Garriott, video game designer, space tourist and son of Skylab and Space Shuttle astronaut Owen Garriott, bought the lander and the rover at a Sotheby’s auction for $68,500 in 1993. He’s currently the only person to own a piece of space hardware on another celestial body.

This is a great week to begin a full lunation (moon phase) observation. New Moon is Tuesday night Every day, watch the moon grow from a very thin crescent up to the first quarter.

Media Files:

What’s in a Name? st-th

Tue, 09 Jan 2018 14:54:48 +0000

Eighty-six new star names have been approved by the International Astronomical Union, an association of professional astronomers. The names are drawn from ancient mythologies and historical star names from indigenous cultures around the world, including China, Australia, and Southern Africa.

Media Files:

New Year’s Revolutions st

Fri, 29 Dec 2017 19:01:44 +0000

Dr. Pitts and Dave Heller recap their top astronomy stories of 2017:
Astronomers were elated this year when the three operational gravitational wave observatories around the world all reported detecting gravitational waves from the collision of neutron stars and interactions between super-lightweight black holes in the outer reaches of the universe, adding yet another layer to our understanding of how the universe was created and has evolved.
This year, the continental United States experienced its first trans-continental total eclipse in nearly 100 years. It was intentionally observed by more people than any other science event in history. The next total solar eclipse visible in the US will occur on April 8, 2024.

In 2018, watch for the scheduled launch of the James Webb Space Telescope.

Media Files:

The Winter Solstice is At Hand st-th

Mon, 18 Dec 2017 15:40:48 +0000

Monday, December 18 is the new moon of the year’s last lunar cycle. The moon will be in the 1st quarter by Christmas Eve. If you’re up late wrapping presents on Christmas Eve, or up early to open gifts on Christmas morning, in the East there will be lots of stars visible, as well as Mars, Jupiter and Mercury.
President Donald Trump signed a space policy directive last week formally directing NASA to return humans to the moon, then to use that experience to attempt a visit to Mars. This further refines NASA’s direction for deep solar system exploration in that it clearly leans on a ‘stepping stone’ approach to solar system exploration starting with the moon. But with one hand he giveth and with the other he taketh away; the humans-to-an-asteroid mission is dead.
Trump’s declaration applies only to the national space agency; it has no effect on commercial space companies, several of whom are still pressing forward with plans to get to Mars sooner than NASA. Last week, Jeff Bezos’ Blue Origin rocket company conducted a successful test flight.

Media Files:

Geminid Meteor Shower st-th

Tue, 12 Dec 2017 16:24:27 +0000

The Geminid meteor shower peaks Wednesday and Thursday this week with upwards of 100 meteors per hour.
The moon is a very thin waning crescent and should look really nice under a clear sky.
Orville Wright flew the first powered flight 114 years ago, on December 17th, 1903.

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Earliest Sunset st-th

Mon, 04 Dec 2017 19:05:20 +0000

Sunset comes at 4:35pm this week, then gradually later and later, though it won’t be until early January before we really start to see gains in hours of daylight.

5 weeks ago, astronomers across the world were surprised to find a sizable interloper zipping through the solar system. It’s not unusual to discover a new comet but it really raises eyebrows – and telescopes – when that object seems to come from an entirely different star system! Oumaumau’s trajectory, velocity, shape and suggested composition brand it as not being a comet, but an asteroid. Its shape, reflectivity and non-reaction to its close fly-by of the sun all point to the rockier options. Observers around the world dropped what they were doing to get the best possible view of this one because it seemed…well, odd.
The interstellar object is ten times as long as it is wide and reflects just 4% of sunlight. It’s traveling at a brisk 98,000 mph, a trajectory that suggests it comes from the constellation Lyra. This could be an interstellar asteroid – the first ever seen.

Mars and Jupiter own the pre-dawn sky this week.

Media Files:

Getting Closer to Finding Another Earth st-th

Mon, 20 Nov 2017 15:24:46 +0000

The planet Ross 128 is 11 light-years away and 1.35 times the mass of Earth and orbits its red dwarf star every 9.9 days.
Initial data suggest this is a liquid water planet, inside the star’s habitable zone – a very important requirement for finding life.
The upcoming new generation of giant ground-based telescopes should be able to image Ross 128 and study its atmosphere for methane, oxygen and other telltale signs of either life (as we know it), complex compounds or just the conditions conducive to the development of life. THAT would be a new accomplishment.

Today is the 128th birth anniversary of Edwin Hubble – he determined that the universe has more than one galaxy and that those galaxies are moving outward, some at incredible rates of speed – revealing the previously unrealized expansion of the universe.

Jupiter, Venus, and Mars have the pre-dawn sky this week from 6am to sunrise. The moon and, strictly speaking Saturn and Mercury, hold court weakly and very low in the west at sunset.

Media Files:

Where there’s water… st-th

Tue, 14 Nov 2017 15:02:54 +0000

Scientists have discovered a new suggestion of habitability in the ocean of Saturn’s moon Enceladus. Early doubts about tidal friction providing adequate heating for water jets is now supplemented by the suggestion that an unconsolidated core would allow penetration of water from the surrounding ocean and frictional heating derived from tidal interaction with Saturn. It’s valid to surmise this mechanism has been been functioning for a billion years and so a (relatively) warm ocean environment could’ve been in place for a billion years or more, maybe long enough to allow the development of life forms. On Earth, it’s estimated that the first microorganisms emerged after just 500 million years, with hydrothermal vents playing a key role in supplying heat and minerals.

A long-lasting supernova has been discovered – While supernovas typically are ‘one and done’, observations of a supernova that just won’t die indicate perhaps a new type of supernova, one that takes several explosions, maybe over decades, to blow off enough material to finally give up the ghost and begin to dim and cool.

Media Files:

Water, Water Everywhere! st-th

Tue, 07 Nov 2017 16:08:31 +0000

Studies of asteroids are revealing that they might have a watery history. The DAWN spacecraft orbiting Ceres has provided data that suggests water was a major ingredient in the formation and evolution of the crust and mantle of the dwarf planet. This suggests that water is a much bigger player in the solar system than ever thought before.

A Philadelphia-sized lava tube has been identified on the moon, by the Japanese lunar orbiting satellite Selene. Gravity studies indicated its presence. This is an important discovery because Vice President Pence has indicated that the Trump administration will be far more focused on returning to the moon than with pushing for exploration of Mars. Tubes become important in that they can provide needed shielding of human outposts.

Media Files:

Rogue Comet Comes a-Calling ison-approach-th

Mon, 30 Oct 2017 14:57:51 +0000

Not merely out-of-this-world, a comet from beyond our solar system came and went earlier this month.
Cross-quarter-day approaches…wait, what’s cross-quarter day?
A NASA program invites subscribers to become ‘Martians’ by sending their name to Mars on the next exploratory mission, Insight. The mission launches in May 2018, lands November 2018. InSight will study the interior of Mars.

Media Files:

Pluto: The non-ringed non-planet Solar System - Planet Pluto.

Mon, 23 Oct 2017 15:22:32 +0000

We begin with the story of Spitz Laboratories, based in Chadds Ford, Pennsylvania. In the 1960s, the space race kicked off a nationwide surge of interest in astronomy. Schools began to build planetariums, and in Pennsylvania Spitz Laboratories built so many that in the 60s and 70s Pennsylvania had more in-school planetariums than New York and California combined.

Scientists have declared conclusively that Pluto has no rings. This is good news for their Horizons mission, as it means fewer obstacles for the craft to navigate as it heads towards its next destination, a space rock in the Kuiper belt.

Mars and Venus are visible in the predawn sky. Saturn can be seen in the Southwest after sunset.

Media Files:

Out-of-this-world show st-th

Mon, 16 Oct 2017 14:35:17 +0000

This Saturday marks the 94th anniversary of the first public planetarium show given at the German model for The Franklin Institute, the Deutches Museum in Munich.
Our planetarium opened on January 1st, 1934 as the second planetarium in the United States, after the Adler planetarium in Chicago (1930).
An apocryphal story is that Sam Fels traveled to Europe with Max Adler in the late 20’s where he saw the star projection system. He was so taken with the idea that he ordered one for Philadelphia without a place for it. He approached The Franklin Institute, which was in the planning stages for their new building at 20th street and the Benjamin Franklin Parkway.

Mars and Venus are now well separated in the pre-dawn eastern sky 6:30 a.m. A very thin waning crescent moon is just to the left of Mars on Tuesday morning and sneaks past Venus during the day.

Media Files:

Elon Musk wants to get off this planet Space Travel

Mon, 09 Oct 2017 20:23:45 +0000

Elon Musk has released a new proposal for becoming a multi-planet species. He is advocating phasing out Falcon 9, Falcon Heavy and Dragon in favor of SpaceX’s BFR (Big F*****g Rocket-yes, really) project, which can serve as Mars transport, Lunar transport, ISS transport, and satellite delivery as well as SST Earth transport. The rockets will be reusable, bigger and cheaper to operate than any other rocket system ever. Supposedly. Musk says SpaceX can send the first two to Mars by 2022, and send four more to Mars, with explorers, by 2024. He also thinks he has a way to pay for this: Continued satellite launch services and ISS transport services.

The James Webb Space Telescope launch postponed until 2019. It was originally scheduled for launch in 2010/2011, then October 2018. Now due to payload integration schedule challenges, Spring 2019 looks like the next target period for launch. It’s critically important to get everything not just right, but perfect. Unlike many other missions that have allowed software uplinks and upgrades well into the mission after leaving Earth and even on-orbit servicing at 400 miles up as with HST, the JWST will be 930,000 miles up, well out of reach for any kind of servicing.

With sunset coming so much earlier now and the evening temps staying comfortable, you should find a way to get out to see a dark evening sky, especially the Milky Way. We’re viewing it almost on-edge as we look down toward Sagittarius.

Media Files:

Mercury runs hot and cold Perspective View of Mercury's Topography

Fri, 06 Oct 2017 14:54:32 +0000

Today, Dave and Dr. Pitts are stopping by the ice craters of Mercury, the planet closest to the Sun. Temperatures on Mercury typically hover around a balmy 800 degrees Fahrenheit, on the side facing the Sun. Yet there are at least 100 billion tons of ice on the little planet. How is this possible? The answer lies in Mercury’s lack of atmosphere. Without an atmosphere, heat is not conducted to the parts of the planet that aren’t getting direct solar radiation. The side of Mercury that doesn’t face the sun has a temperature of 300 degrees below zero. The abundance of ice can be found in craters at Mercury’s poles. The craters are always in shadow, so they receive no solar radiation.

Media Files:

America’s Most Experienced Astronaut Space Record Whitson

Mon, 11 Sep 2017 19:50:43 +0000

Let’s sing the praises of NASA superstar Peggy Whitson! Now back on Planet Earth after 288 days in space, she’s now the most experienced U.S. astronaut with 665 days on orbit. That’s 131 days more than her nearest competitor, Jeff Williams. Whitson has also logged 60 hours and 21 minutes of cumulative spacewalk time!
She has also been named Commander twice and has the most time on spacewalks for any woman astronaut…the list of superlatives goes on.

NASA’s Cassini is on its final orbit now, heading to destruction on Friday morning. It is expected to fragment under impact stress while still transmitting data about the interior of Saturn as it goes.

Media Files:

Bon Voyager st-th

Tue, 05 Sep 2017 14:47:13 +0000

Voyager 1 left Earth 40 years ago, on September 5th, 1977. Voyager 2 left first, on August 20th. Amazingly, both are still functioning. They are getting ever closer to the edge of the solar system.
51 years ago Star Trek premiered in Sept 1966, 3 seasons, 79 episodes. Low Nielsen ratings killed it, but it became a hit in syndication, then a cult classic from which every other space tv program and movie grew.

Media Files:

Following Florence st-th

Tue, 29 Aug 2017 14:38:39 +0000

Asteroid Florence will pass Earth on Saturday. At 2.4 miles in diameter, it’s the largest since researchers began keeping close tabs on near-earth asteroids. The asteroid will pass us by at 18 times the distance from Earth to the moon – not close at all!
The last time Florence passed was in 1890, and it won’t again until 2500.
Cassini starts its last three orbits this week. It’s in its final phase of exploring Saturn before it plunges into the planet on Sept. 15th ending its 13 years at Saturn. September 2nd will be its second to last orbit – #292, its closest orbit. Several orbit-height-adjustment maneuvers are planned depending on the density of Saturn’s upper atmosphere during the final orbits. The spacecraft was only supposed to last 4 years but its mission was extended three times
Jupiter hangs very low in the west just after sunset with Saturn still well up in the south. Venus dominates the pre-dawn sky – Mercury and Mars are there but too close to the sun to be visible. Cool astro targets for binoculars in late summer – Cluster in Hercules, galaxy in Andromeda.

Media Files:

Diminished Daylight in the Dog Days st-th

Mon, 14 Aug 2017 14:13:24 +0000

We’ve now lost 25 minutes off sunsets and 30 minutes off sunrises – that’s an hour daylight change already from the solstice.
Jupiter and Saturn still dominate the evening sky; Jupiter is losing to sunset though. Venus has the pre-dawn covered, rising around 3:30 a.m.
Cassino is making its final orbits around Saturn, before plunging into the planet next month.
This is the 40th anniversary of Voyager’s launch – now approaching the outer limits of our solar system.
Opportunity has been roving on Mars for 13 years, 28 miles. What’s next? Now on the edge of Endeavor Crater, the craft will try to gather evidence to understand how the gullies were created – by water or by some other mechanism.
Last week of prep before the total solar eclipse across the United States.

Media Files:

Total Tune-Up st-th

Mon, 07 Aug 2017 14:44:51 +0000

Monday’s lunar eclipse is the precursor to the August 21 total solar eclipse that will traverse the United States. Dr. Pitts and Dave Heller discuss celestial mechanics and proper eclipse-viewing safety. Saturday is the peak of the Perseid Meteor Shower, making this a great week for astronomy!

Media Files:

Follow the Sun skytalk

Mon, 31 Jul 2017 17:27:52 +0000

We are now just three weeks out from a total solar eclipse traversing the United States. Those lucky enough to be in the direct path will experience totality for some 2-and-a-half minutes. NASA will stretch that totality to over eight minutes by flying a retired bomber aircraft to chase the solar eclipse Monday 8/21. Their intent is to study the corona in Hi-Res Infra Red and Visible light to try to understand why, if the corona is so hot (millions of degrees), it is so uniform and organized. NASA will also will look for asteroids near the sun and Mercury.

Brown University scientists have identified additional water signatures on the moon. Indication from analysis of surface lava flows suggests that the mantle of the moon contains larger amounts of water than previously expected. There are potential implications for use of the moon as a forward base of exploration of the solar system.

Media Files:

Shine on, you crazy Earth st-th

Mon, 24 Jul 2017 14:07:07 +0000

This is a great week to watch the development of lunar phases. Start watching on Monday night, with a barely visible 1.5-day old thin crescent that sets about an hour after the sun; you should see it near the western horizon at 8:30 P.M. On Monday and Tuesday night, you’ll have a great display of “Earthshine.”

New Horizons is on a billion-mile cruise to MU69, a Kuiper Belt Object that’s been selected as the next object the satellite will fly by in 2019. The spacecraft left Earth in January 2006 at 36,000 mph – that’s 100 times faster than a jetliner.
Mark your calendars! We are now just one month out from the Great American Eclipse.
Apollo 11 returned to Earth on July 24th, 1969. Apollo 15 Left for the moon on July 25th 1971, and arrived 4 days later. It was the fourth lunar landing mission and the first to use a rover.

Media Files:

Shining Star (but just barely) Star Field in the Constellation Cepheus

Tue, 18 Jul 2017 13:55:37 +0000

The smallest star ever just found, called ELBM-J0555-57Ab, is just about the size of Saturn but 300 times as massive. That makes it just 8% of the sun’s mass, yet it’s just big enough to actually BE a star according to thermonuclear fusion principles.

48 years ago this week, Neil Armstrong and Buzz Aldrin walked on the moon. They spent 21 hours on the moon and were outside just 2.5 hours.

The Juno spacecraft orbiting Jupiter flew over the Great Red Spot last week. Just 2,200 miles above the cloudtops, the photos released last Friday show amazing detail. Scientists hopefully will learn more about the great storm and Jupiter’s inner atmosphere.

A thin crescent moon joins Venus in the pre-dawn sky on Thursday. From 4:40 a.m. to 4:50 a.m. you’ll also see ISS fly from NNW to E and it goes right under Venus and the moon!

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It was 20 years ago today… Color Mosaic of Rover & Terrain

Mon, 10 Jul 2017 14:11:31 +0000

On this date in July 1997, NASA placed the first rover on Mars. Sojourner was followed by Spirit and Opportunity, then Curiosity. It was preceded by Vikings I and II. All lasted far longer than expected.
Today 55 years ago, Telstar, the first TV communications satellite, launched.
And 48 years ago Sunday, Apollo 11 left for the moon. It landed 4 days later.

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Let’s Get Elliptical st-th

Mon, 03 Jul 2017 04:32:19 +0000

This week, Dave Heller and Dr. Derrick Pitts discuss Earth’s elliptical orbit, and how it can still feel hot on Earth when we are at our farthest distance from the sun.

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You Must Remember This – An Eclipse Is Not Just an Eclipse st-th

Mon, 26 Jun 2017 14:50:59 +0000

Kepler scientists this week announced the 219 newest additions to the exoplanet count – 10 of which are identified as “terrestrial” – a far better word to use than “earthlike.” Terrestrial meaning rocky, comparable to earth in size, and in their star’s habitable zone. The total number of planet candidates now? 4,034. Confirmed? 2335 verified as planets. Kepler first looked in the Cygnus constellation region for these discoveries and this latest addition represents the end of its work in Cygnus. One conclusion – Half the planets in our galaxy are either rocky and larger than Earth or are like Neptune, smaller giant gas planets.

Next Monday is Aphelion: the follow-up to the summer solstice. Even now, we’re sitting right at 15 hours of sunlight per day, with long evenings.

The August 21st Solar Eclipse is less than 2 months away. Locally, it’ll be just partial. For totality, your closest vantage point is South Carolina, just a 12-hour drive from here. More information at

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Twice Upon a Time… st-th

Mon, 19 Jun 2017 14:55:56 +0000

Sun’s Original Twin: What happened to it? UC Berkeley astronomer Steven Stahler and Sarah Sadevoy of Smithsonian Astrophysical Observatory, have been studying how single stars form. Data collected in different surveys of the Perseus stellar nursery supports a model in which single stars seem to form first as binaries, then, depending on the distance between the stellar nuclei, they either stick together as binaries or break apart becoming single stars. The new study suggests this is how all single, low mass stars – sunlike stars – originally develop. So what happened to our star’s sibling? Because of the extreme distance between the two – 17x the distance between our star and the planet Neptune- the two nascent stars separated. One became our star while the other moved off to become one of the many other stars in this region of the Milky Way.
Once the sun formed, which planet came first? According to astronomer Thomas Kruijer of University of Munster Germany and Lawrence Livermore Labs in California, it’s …Jupiter!
The Summer Solstice arrives on Wednesday at 12:24 am. The Solsitce occurs when Earth reaches a point in its solar orbit where the rotational axis is at its maximum northern tilt towards the sun. The tilt allows apparent path of the sun across the sky to have a larger arc of travel, providing more hours of daylight. We’re up to 15 hours and 42 seconds of daylight, which is 5 hours and 40 minutes more than Winter Solstice.
Sunset dwells at 8:33 until July 4th, then starts to drop back.
By 10 p.m., Saturn is now well up in the southeast with Jupiter in the southwest.
On Wednesday morning at 4:45 a.m., the thin waning crescent moon and Venus are together just before sunrise.

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Some Like it Hot st-th

Mon, 12 Jun 2017 14:57:10 +0000

If you’re sweating from our current heat wave, be glad you don’t live on planet KELT-9, orbiting a blue A-type star 620 light years from Earth.
KELT9b is the hottest gas giant planet ever found, with a surface temperature of 7,800 degrees Fahrenheit; hotter than most stars!
KELT-9 is tidally locked so that one side is literally boiling – the UV radiation is so intense that heavier molecules like water, CO2, or methane can’t form. The star itself is twice as large and twice as hot as our sun – over 20,000 degrees Fahrenheit. The blast from the sun is so intense, the gas of the gas giant is probably being blown away – evaporated or vaporized! At 300 million years old, the star is quite young, EXCEPT it is a Blue type A – it won’t last long at all.
On the opposite end of the spectrum, a planet at TRAPPIST-1, h, is far enough away from its too-cool star (6 million miles) that its surface temperature is -148 degrees Fahrenheit.

Saturn’s got the swing shift! Jupiter, then Saturn by 10p, by 4:30 a, Saturn in the west and Venus in the east – Saturn’s the planetary pivot of the sky! Anybody notice last week’s mini-moon? Didn’t think so… the difference in size was too small to notice!

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Philadelphiahenge st-th

Mon, 05 Jun 2017 15:00:42 +0000

Wiltshire, England doesn’t have the monopoly on solar events with summer solstice at Stonehenge. Philadelphia is a suitable site to take in an Equinox spectacle.
With sunrise at 5:32am on Monday and sunset at 8:26pm, the sky isn’t totally dark until almost 9 pm. We have nearly 16 hours of visible light this time of year.
Night Skies at the Observatory will happen two nights per month at the Franklin Institute this summer. Come learn about the night sky and see the two gas giants Jupiter and Saturn. Both are visible from 10pm through 3am on any clear night.

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Ring Around the Sun st-th

Tue, 30 May 2017 00:38:43 +0000

A cosmic debris ring has been observed around a star where a planet has already been directly observed.
Plus, the observed lunar inventory in our solar system is boosted thanks to a faraway discovery.

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Longing for longer days st-th

Tue, 23 May 2017 13:46:47 +0000

Sunset now comes at 8:15pm, giving us 14 hours and 36 minutes of daylight here at Philadelphia’s latitude.
We have about four weeks to go and 30 more minutes of daylight to earn on the way to Summer Solstice.

On Wednesday morning Venus, Uranus, Mercury and the Moon can be seen low in the east at 4:45 AM, along with a very bright ISS from Northwest to Southeast!

Astronomical Anniversaries of note;
May 28, 1959: The first primates flew into space – Able the rhesus monkey and Baker the squirrel monkey made suborbital flights.
Two years later on May 25th, JFK gave his now-famous Moon Landing speech. “…before the decade is out…”.
On May 22 1969, Apollo 10 descended to within 50,000 feet of the lunar surface in preparation for Apollo 11’s historic mission just 60 days later – July 20.

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Think Big by Going Small st-th

Tue, 16 May 2017 14:29:18 +0000

How can we get into outer space faster? Nanocraft! The $100 million Breakthrough Starshot initiative intends to develop, within a generation, the capability to launch tiny laser-propelled space probes to the nearest star. The 1 gram, postage stamp-sized chips would have all the electronics necessary to collect data and transmit information back to us from the nearest star system. Driven by 100-gigawatt laser, the chips would accelerate up to 20% of the speed of light in two minutes and get them to the star in 20 years. Fronted by billionaire Yuri Milner and supported by Stephen Hawking and Mark Zuckerberg, the proposed project could cut 29,980 years off a conventionally propelled probe out to Alpha Centauri.

Gemini stands on the western horizon at 9:30 now, the last of the winter constellations. Mars is gone for this season of planet viewing, replaced by Jupiter immediately visible after sunset. By 12:45a Jupiter is well up in the south, with Saturn above the SE horizon stuck in the Milky Way portion of the sky between Sagittarius and the stars of Scorpius. Leo is in the NW, with UMaj – The Big Dipper, higher up in the north.
The moon sits in the day time sky – an unexpected phenomenon.

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Summer Sky Season Beckons st-th

Mon, 08 May 2017 13:51:44 +0000

With the return of the summer constellations rising around midnight, the Milky Way rises up from ringing the horizon and will arc slowly across the night sky. We look to the west in one direction away from our galactic arms and in the opposite direction to the east as if we’re the hub of the wheel and the tire rolls around us but we’re way out near the far edge of the Milky Way with center being towards Sagittarius, found in our southern sky.
This week’s anniversary: 88 years ago, the Adler planetarium, America’s first planetarium, opened in Chicago.

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May Day, May Day! st-th

Mon, 01 May 2017 14:01:26 +0000

Now more commonly observed as a celebration of spring, in older times May 1st was considered the first day of summer in some European countries, with February 1 as the first of spring and June 21 marking midsummer.
Anniversaries: On May 5th 56 years ago, Alan Shepard was the first American to enter outer space. 51 years ago Neil Armstrong ejected safely from the ‘Flying Bedstead’ (a nickname for NASA’s Lunar Landing Research Vehicle) while training for his upcoming lunar mission.
Cassini starts its final orbits of Saturn. Last week, the Cassini mission flew its last orbit around Titan, Saturn’s largest moon. Now it will spiral around Saturn, one orbit per week, between the innermost D-ring until September 15 when it finally plunges into Saturn. Cassini was launched from Earth in 1997, arrived at Saturn in 2004, and has been exploring there ever since.
Mars is holding on by its fingernails at sunset now (8:30p) along with Orion. Jupiter and Spica of Virgo ride the night sky together. Orange Arcturus is now well up in the east at sunset. The summer constellations and Saturn are above the horizon by midnight, while Saturn and Venus now bookend the 5 a.m. sky.

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Dee-Dee-lightful 3.6-m Telescope at La Silla

Mon, 24 Apr 2017 13:55:06 +0000

The Blanco reflector telescope at Cerro Tololo in Chile has detected a ‘distant dwarf’ planet observers are calling “DeeDee.”
It was discovered during the “Dark Energy Survey” of 12% of the sky looking for dark energy sources. “DeeDee” was slowly moving through the telescope’s field of view.
Further observations with the Atacama Large Millimeter/Submillimeter array, also in Chile, indicate it’s spherical in shape, about 635 kms across, and three times Pluto’s distance from the sun.
Curiosity Stream’s New Program “Miniverse” features Physicist Michio Kaku(City University of New York), Laura Danley (Curator of Griffith Observatory in LA), and Dr. Pitts conducting a mini-tour of the solar system with Canadian astronaut Chris Hadfield.
Another reminder; amateur astronomers are the stars this Friday night as they bring their knowledge and equipment to a neighborhood near you during the City Astronomy Night; one of the signature events of the Philadelphia Science Festival.

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The March for Science France Climate Countdown

Mon, 17 Apr 2017 19:56:31 +0000

Science takes center stage Saturday, April 22 in marches planned across the country. Philadelphia will host its own local science march from City Hall to Penn’s Landing.

The Philadelphia Science Festival begins Friday, April 21. The festival brings 80+ free or nearly free activities and programs to locations all over the city. The 10 day long event culminates with the city-wide astronomy night on the 28th and the Science Carnival at Penn’s Landing on the 29th.

Jupiter, Mars and Saturn are all visible in the night sky this week.

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Planet Nine, where are you? st-th

Tue, 11 Apr 2017 13:31:36 +0000

Ever since Pluto was demoted from the pantheon of planets, efforts have intensified to designate a replacement. Scientists have detected the presence of…something…about 10 times the mass of Earth and 1000 times the distance between the Earth and the Sun. Australian researchers mounted a campaign to find the big guy using the SkyMapper telescope at Siding Spring Observatory. The search yielded hundreds of thousands of images that were then sifted by tens of thousands of volunteers, and out of that pile have emerged 4 candidate objects that might be the elusive Planet Nine.

Mars after sunset in the west, Jupiter by 9 p.m. in the east and Jupiter, Saturn, and Venus at 5:15 a across the sky.

The Night Sky Observatory at the Franklin Institute this Thursday evening features astrophysics powerhouse and scientific visualization specialist Dr. Frank Summers.

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The Need for Speed st-th

Wed, 05 Apr 2017 13:39:08 +0000

A star has been discovered that orbits a black hole once every 28 minutes. Not impressed? This star is 2.5 times farther away from the black hole than the moon is from Earth, and the moon orbits the Earth only once every 27 days.

Scientists believe they have discovered a new way that stars are formed. A black hole spits out particles and gases at a blistering 94 million miles per hour. That seems pretty fast, until you realize that’s only 14% of the speed of light. Scientists think that new stars could be formed in those high-speed jets of matter.


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Cutting Corners Space Station

Mon, 27 Mar 2017 13:58:49 +0000

President Donald Trump’s proposed 2018 budget cuts NASA’s funding by 1%. What’s lost? Some Earth Observing missions, the Asteroid Redirect Mission, and the NASA Office of Education.
Stephen Hawking has been offered a free trip to space by Richard Branson aboard the Virgin Galactic space flight system currently under development. Test flights are still being conducted and Hawking’s flight is years away at best.
Venus is gone from the evening for observing until next year. But wait: the next sighting opportunity for the planet is…..just 10 days from now when it shows up in pre-dawn skies!

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Tilting toward the summer season t-th

Tue, 21 Mar 2017 13:57:21 +0000

Monday was an important day for folks who are sick of winter—the Vernal (or Spring) Equinox! The tilt of Earth’s rotational axis allowed for equal hours of daylight and darkness.

What does this look like at the equator? At the North Pole? How about the South Pole? Little discrepancies distort the true meaning of the word “equinox.” The hours of daylight and darkness are more equal at the equator than at the poles.

Pan,  Saturn’s ‘flying saucer’-shaped moon was photographed by the orbiting Cassini spacecraft. This orbits as a shepherd moon in the 325-mile-wide space known as the Encke Gap.  See images here:

Venus is almost gone from the night sky; it exchanges positions with Mercury while Mars is still hanging. Jupiter well up by 10 PM. Pre-dawn Saturn and Jupiter sit in the south and south-western sky at 5:45 AM.

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