Light Echoes from V838 Mon
For reasons unknown, star V838 Mon’s outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this has never been seen before.
It’s true that supernovae and novae expel matter out into space. But while the V838 Mon flash appears to expel material into space, what is seen here is actually an outwardly moving light echo of the bright flash. In a light echo, light from the flash is reflected by successively more distant rings in the ambient interstellar dust that already surrounded the star.
V838 Mon lies about 20,000 light years away toward the constellation of Monoceros the unicorn. In this Hubble Space Telescope image from February 2004, the light echo is about six light years in diameter.
Image Credit: NASA, APOD, ESA, H. E. Bond (STScI)
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When NASA scientists announced earlier this year that they had found evidence of liquid water on Mars, imaginations ran wild with the possibility that life could exist somewhere other than here on Earth.
Scientists continue to explore the possibility that Mars once looked a lot like Earth — salty oceans, fresh water lakes, and a water cycle to go with it. That’s exciting stuff.
So where else are they looking? What exactly are they looking for?
There are nine places in our universe where scientists say life is a possibility. The locations range from a smoking hot planet like Venus to a moon that orbits Saturn called Enceladus, which looks a lot like a massive, tightly-packed ball of ice.
All of these places show signs that water is, or at least was, a possibility. They also appear to feature some kind of energy that could produce heat.
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The Infrared Visible Andromeda: This remarkable synthetic color composite image was assembled from archives of visible light and infrared astronomy image data. The field of view spans the Andromeda Galaxy are also included in the frame. via NASA
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At the Heart of Orion.
Timelapse of Europa & Io orbiting Jupiter, shot from Cassini during its flyby of Jupiter