SOFIA, or the Stratospheric Observatory for Infrared Astronomy, is a modified 747 with a 2.5 meter infrared telescope.
The Big Asteroid We Know Little About
Euphrosyne is the 5th most massive asteroid in the solar system. It has the highest density of any asteroid, so it’s only the 12th largest in terms of diameter. Despite its size, however, we actually don’t know that much about Euphrosyne.
All Alone in the Night
Although we think of deep space as being dark, that isn’t entirely true. The universe is filled with a background glow of radiation. The most famous is the cosmic microwave background, which is the remnant glow of the big bang. There is also the x-ray background, caused by things like active galactic nuclei, the radio background. This week new research on the infrared background has been published in Science, and the results are somewhat surprising.
Shadow Facts
Usually in astronomy we study objects by the amount of light they emit. Most regular matter gives of light in some form or another. Even the cold interstellar medium will emit some light at infrared or radio wavelengths. But one downside of this is that the light generally comes from the surface regions of an object. To study the interior of an object we generally have to use aspects of emitted light from the surface to determine properties of the interior. For bright objects like stars this works pretty well, but for dim objects like dark interstellar clouds this is more of a challenge.
Hidden Giants
When WISE completed its full sky survey, about 1.6 million “hidden” black holes were discovered. Some of these are billions of light years away, which will help give us a better understanding of how these supermassive black holes evolve within galaxies.
Hot Rocks
Asteroids come in a range of sizes, from hundreds of kilometers in diameter down to a meter wide and smaller. Determining just how many asteroids there are is a challenge, because the smaller an asteroid’s size, the more difficult it is to observe.