Uploaded June 2010 | Updated September 2026, 1 week ago
facebook.com/ScienceReason ... The Hidden Universe of the Spitzer Space Telescope (Episode 33): When Worlds Collide.
When worlds collide, the result is spectacular, and astronomers think they've detected the aftermath of such an event around another star.
This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.
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Nearly 60 years ago, audiences thrilled to the destruction of the Earth in George Pal's classic film, "When Worlds Collide." The idea of a planetary smash-up is a staple of science fiction, but can it really happen? Astronomers using NASA's Spitzer Space Telescope think they've actually seen the aftermath of such a collision around another star. It can even help us understand similar calamities that happened long ago in our own solar system.
The story unfolded as Dr. Casey Lisse and his team studied disks around young stars. Once planets have formed astronomers think there are a lot of left-over asteroids in the system. They occasionally slam together and produce dusty debris. Spitzer's Infrared Spectrograph was designed to detect the faint glow from this material. By spreading the light out into its component colors, astronomers can look for the spectral fingerprints of different minerals. This way we can figure out the composition of disks around other stars.
Our dusty star of interest is a faint speck known as HD 172555. It's about 100 light years away and 12 million years old which, compared to our 4.5 billion year old Sun, is like a baby born a few days ago. Studying its spectrum, Dr. Lisse and his colleagues realized they had found something very peculiar that they had not seen around other stars. Aside from the usual indicators of rocky rubble, they found features corresponding to tektite, obsidian, and silicon monoxide gas.
What's strange is that tektite and obsidian are formed from molten materials. Tektites are hardened chunks of lava found around meteor impacts on Earth, and obsidian is volcanic glass. Vaporized rocks can form silicon monoxide gas. You don't get this kind of material by just smashing a couple of asteroids together. The evidence suggests something much more... cataclysmic.
Imagine what would happen if our moon slammed, at high velocity, into a Mercury-sized planet. The resulting impact would eject a massive amount of molten material into space. As it cooled it would likely form tektite, obsidian, and silicon monoxide gas, explaining the features seen in the HD 172555 spectrum.
It's amazing to think Spitzer may have caught the aftermath of such an incredible collision. But, it's not the first time astronomers have speculated about world-shattering events. Things like this may have happened right here in our own back yard.
Mercury is a strangely dense planet compared to the other rocky worlds in our solar system. If it formed from the same stuff as Venus and Earth, why would it be different? A world-shattering impact could be the answer. When planets form the lighter materials rise and denser ones sink to the core. Remove the outer, lighter layer, and you're left with a denser planet, once what's left cools off.
Looking to our neighbor Mars we see a massive impact scar in its Southern hemisphere. This area, known as the Hellas Basin, must have formed from an asteroid impact long ago. The resulting plume of molten material would have been blasted into space, some of it eventually reaching the ancient Earth.
Even closer to home, most astronomers believe that our own moon was the result of a similar cataclysm. The theory is that a Mars-sized body grazed the stillforming Earth, generating a massive amount of molten debris. The orbiting rubble would have clumped together over time, forming the moon.
The tektite and obsidian debris from such massive impacts would not last long in our solar system, or others. Solar winds and gravitational interactions tend to sweep away the dust over time, and in a few tens of thousands of years the evidence would be erased.
In the long history of our solar system, that's hardly an eyeblink. The evidence may be long gone here, but seeing what may happen when worlds collide around a nearby star shows us it's not just science fiction after all.
Credit: NASA/JPL-Caltech
• http://spitzer.caltech.edu
.
facebook.com/ScienceReason ... The Hidden Universe of the Spitzer Space Telescope (Episode 33): When Worlds Collide.
When worlds collide, the result is spectacular, and astronomers think they've detected the aftermath of such an event around another star.
This is the Hidden Universe of the Spitzer Space Telescope, exploring the mysteries of infrared astronomy with your host Dr. Robert Hurt.
---
Please SUBSCRIBE to Science & Reason:
• youtube.com/Best0fScience
• youtube.com/ScienceTV
• youtube.com/FFreeThinker
• youtube.com/RationalHumanism
---
Nearly 60 years ago, audiences thrilled to the destruction of the Earth in George Pal's classic film, "When Worlds Collide." The idea of a planetary smash-up is a staple of science fiction, but can it really happen? Astronomers using NASA's Spitzer Space Telescope think they've actually seen the aftermath of such a collision around another star. It can even help us understand similar calamities that happened long ago in our own solar system.
The story unfolded as Dr. Casey Lisse and his team studied disks around young stars. Once planets have formed astronomers think there are a lot of left-over asteroids in the system. They occasionally slam together and produce dusty debris. Spitzer's Infrared Spectrograph was designed to detect the faint glow from this material. By spreading the light out into its component colors, astronomers can look for the spectral fingerprints of different minerals. This way we can figure out the composition of disks around other stars.
Our dusty star of interest is a faint speck known as HD 172555. It's about 100 light years away and 12 million years old which, compared to our 4.5 billion year old Sun, is like a baby born a few days ago. Studying its spectrum, Dr. Lisse and his colleagues realized they had found something very peculiar that they had not seen around other stars. Aside from the usual indicators of rocky rubble, they found features corresponding to tektite, obsidian, and silicon monoxide gas.
What's strange is that tektite and obsidian are formed from molten materials. Tektites are hardened chunks of lava found around meteor impacts on Earth, and obsidian is volcanic glass. Vaporized rocks can form silicon monoxide gas. You don't get this kind of material by just smashing a couple of asteroids together. The evidence suggests something much more... cataclysmic.
Imagine what would happen if our moon slammed, at high velocity, into a Mercury-sized planet. The resulting impact would eject a massive amount of molten material into space. As it cooled it would likely form tektite, obsidian, and silicon monoxide gas, explaining the features seen in the HD 172555 spectrum.
It's amazing to think Spitzer may have caught the aftermath of such an incredible collision. But, it's not the first time astronomers have speculated about world-shattering events. Things like this may have happened right here in our own back yard.
Mercury is a strangely dense planet compared to the other rocky worlds in our solar system. If it formed from the same stuff as Venus and Earth, why would it be different? A world-shattering impact could be the answer. When planets form the lighter materials rise and denser ones sink to the core. Remove the outer, lighter layer, and you're left with a denser planet, once what's left cools off.
Looking to our neighbor Mars we see a massive impact scar in its Southern hemisphere. This area, known as the Hellas Basin, must have formed from an asteroid impact long ago. The resulting plume of molten material would have been blasted into space, some of it eventually reaching the ancient Earth.
Even closer to home, most astronomers believe that our own moon was the result of a similar cataclysm. The theory is that a Mars-sized body grazed the stillforming Earth, generating a massive amount of molten debris. The orbiting rubble would have clumped together over time, forming the moon.
The tektite and obsidian debris from such massive impacts would not last long in our solar system, or others. Solar winds and gravitational interactions tend to sweep away the dust over time, and in a few tens of thousands of years the evidence would be erased.
In the long history of our solar system, that's hardly an eyeblink. The evidence may be long gone here, but seeing what may happen when worlds collide around a nearby star shows us it's not just science fiction after all.
Credit: NASA/JPL-Caltech
• http://spitzer.caltech.edu
.
![NASA Astronomy Pictures Of The Day [Week 5/2010]](https://i.ytimg.com/vi/dltImo5gm38/mqdefault.jpg "NASA Astronomy Pictures Of The Day [Week 5/2010]
http://facebook.com/ScienceReason ... NASA Astronomy Pictures Of The Day [Week 5/2010]
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► Stardust in Perseus
This cosmic expanse of dust, gas, and stars covers close to three degrees on the sky in the heroic constellation Perseus. Right of center in the gorgeous skyscape is the dusty blue reflection nebula NGC 1333, about 1,000 light-years away. At that estimated distance, the field of view is about 50 light-years across. Next to NGC 1333 is the reddish glow of shocked hydrogen gas created by energetic jets and winds from stars in the process of formation.
• http://antwrp.gsfc.nasa.gov/apod/ap100204.html
► Shepherd Moon Prometheus from Cassini
Another moon of Saturn has been imaged in detail by the Cassini spacecraft. Visible in an unprocessed image from 36,000 kilometers away, Prometheus 100-km long surface was revealed to have an interesting system of bulges, ridges, and craters. Cassinis next major targeted flyby is of the moon Rhea.
• http://antwrp.gsfc.nasa.gov/apod/ap100201.html
► Hong Kong Sky
This remarkable scene combines multiple exposures recorded from a waterside perspective in Hong Kong, China. It follows a young crescent Moon, with brilliant planet Jupiter to its left, as they set together in the western sky. Their two luminous trails are faintly paralleled by trails of background stars.
• http://antwrp.gsfc.nasa.gov/apod/ap100206.html
► The Einstein Cross Gravitational Lens
Most galaxies have a single nucleus does this galaxy have four? The strange answer leads astronomers to conclude that the nucleus of the surrounding galaxy is not even visible in this image. The central cloverleaf is rather light emitted from a background quasar. The gravitational field of the visible foreground galaxy breaks light from this distant quasar into four distinct images. The quasar must be properly aligned behind the center of a massive galaxy for a mirage like this to be evident. The general effect is known as gravitational lensing, and this specific case is known as the Einstein Cross.
• http://antwrp.gsfc.nasa.gov/apod/astropix.html
► Mars and a Colorful Lunar Fog Bow
Even from the top of a volcanic crater, this vista was unusual. For one reason, Mars (on the far upper left) was dazzlingly bright when this picture was taken, as it was nearing its brightest time of the entire year.
• http://antwrp.gsfc.nasa.gov/apod/ap100202.html
► P/2010 A2: Unusual Asteroid Tail Implies Powerful Collision
First discovered on ground based LINEAR images, the object appeared unusual enough to investigate further with the Hubble Space Telescope. What Hubble saw indicates that P/2010 A2 is unlike any object ever seen before. At first glance, the object appears to have the tail of a comet. Close inspection, however, shows a 140-meter nucleus offset from the tail center, very unusual structure near the nucleus, and no discernable gas in the tail. Knowing that the object orbits in the asteroid belt between Mars and Jupiter, a preliminary hypothesis that appears to explain all of the known clues is that P/2010 A2 is the debris left over from a recent collision between two small asteroids. If true, the collision likely occurred at over 15,000 kilometers per hour five times the speed of a rifle bullet and liberated energy in excess of a nuclear bomb.
• http://antwrp.gsfc.nasa.gov/apod/ap100203.html
► Dust Storm on Mars
Its spring for the northern hemisphere of Mars and spring on Mars usually means dust storms. So the dramatic brown swath of dust (top) marking the otherwise white north polar cap in this picture of the Red Planet is not really surprising.
• http://antwrp.gsfc.nasa.gov/apod/ap100205.html
► The Colors of IC 1795
This colorful cosmic portrait features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. The nebulas colors were created by adopting the Hubble false-color palette for mapping narrow emission from oxygen, hydrogen, and sulfur atoms to blue, green and red colors, and further blending the data with images of the region recorded through broadband filters.
• http://apod.nasa.gov/apod/ap091210.html
► The International Space Station Over the Horizon
The STS-129 crew of the Space Shuttle Atlantis undocked from the International Space Station (ISS) and returned to Earth. As the shuttle departed the space station, they took the above image. The ISS continues to be home for five astronauts of Expedition 21.
• http://apod.nasa.gov/apod/ap091207.html
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