A new picture combining data from four NASA telescopes is helping to solve the mystery of the "guest star"—a supernova spotted 2,000 years ago by Chinese astronomers.
Formally known as RCW 86, the supernova remnant we see today is two to three times bigger than expected, based on current understanding of how such stellar remains expand.
Now, infrared data from NASA's Spitzer Space Telescope suggest that the explosion happened in a cavity in the surrounding cloud of gas and dust. With no material to slow it down, the supernova's debris spread quickly, leading to the remnant's unusually large size.
Image courtesy SAO/CXC/UCLA/Caltech/ESA/NASA
Multicolored lights dance over the Tasman Sea in a picture of the aurora australis, or southern lights, taken in September from the International Space Station.
Auroras are created when charged solar particles collide with molecules in Earth's atmosphere, infusing the molecules with extra energy that then gets emitted as light. Colors are based on which types of molecules are affected and how high they are in Earth's atmosphere.
In visible light, the cloud of gas and dust has a smooth triangular "mouth" reminiscent of the classic arcade game character. But the new infrared view shows the nebula's lower jaw lined with pillars of dense material that look like jagged teeth—regions where new stars may be forming.
Image courtesy UCLA/Caltech/NASA
Comet C/2009 P1, seen from Italy's Cast Observatory on October 15, is approaching Earth.
Comets are balls of rock and ice that grow tails as they approach the sun in the course of their highly elliptical orbits. As comets heat up, gas and dust are expelled and trail behind them. The sun illuminates this trail, causing it to glow, and thereby making it visible in the night sky, given the right conditions.
Studying pictures of such events can help scientists figure out if the landslides are being triggered by seasonal climate changes, strong winds, or as yet unknown phenomena on the red planet.
Image courtesy U. Arizona/NASA
If you look closely, you can spot four moons in this one picture of the Saturn system recently taken by NASA's Cassini orbiter.
At center, the bright moon Dione stands out against the darker grey of Saturn's largest moon, Titan. The smaller moon Pandora sits to the right, near the edge of part of Saturn's many rings. To the left, the moon Pan appears as a speck within a dark gap in between the rings.
Image courtesy Cassini/ESA/NASA
Satellite's Final Fall
On October 23 the German research satellite ROSAT (picured on October 20) reentered the atmosphere over the Bay of Bengal, though it's unknown whether any parts of the satellite reached Earth's surface.
"With the reentry of ROSAT, one of the most successful German scientific space missions has been brought to its ultimate conclusion," the German Aerospace Center's Johann-Dietrich Wörner said in a statement.
In Antarctica, not all ice is created equal: This recently released picture from NASA's Earth Observing-1 satellite shows several different types of ice in a single frame.
So-called fast ice—named because it holds fast to the shore—fills the right side of the image. This ice is very thick and so appears bright white. Near the edges of the fast ice are icebergs, thick hunks of ice saturated with meltwater, which gives them a bluish tinge.
To the left of the frame is pack ice, which is much thinner and so shows more of the underlying seawater, giving the ice a blue-gray hue. In between the pack ice are swirls of newly formed sea ice called frazil and thin sheets known as nilas.
Image courtesy Jesse Allen and Robert Simmon, EO-1/NASA