I’ve decided to focus my blogging on fewer sites, so that means that I’m bringing Prime Focus to a close. Blogging about astrophotography and awesome space photos will continue on my (new, rebooted) personal blog: see the Astronomy & Space category.
The Mars Express spacecraft performed a flyby of Phobos, the larger of Mars’s two moons (and even so it’s only 27 km across along its longest axis), on January 9, 2011, passing within 100 km of Phobos’s surface, and returning images like these (there’s even a 3D image if you follow the link). Credit: ESA/DLR/FU Berlin (G. Neukum).
The Orion Nebula is one of my favourite things to observe through a small telescope. Things get pretty interesting when you use the Wide Field Imager on the MPG/ESO 2.2-metre telescope at the ESO’s La Silla Observatory in Chile, too. This image combines light taken through hydrogen-alpha, visual and ultraviolet filters. Credit: ESO and Igor Chekalin.
An oblique view of the Moon’s Aitken Crater from the Lunar Reconnaissance Orbiter. Aitken is on the far side of the Moon and is 135 km across; this photo looks over the southwest ridge of its central peak, with the northeast crater walls in the background. Credit: NASA/GSFC/Arizona State University.
Hanny’s Vorwerp, discovered by Dutch teacher Hanny van Arkel in 2007 (“vorwerp” is Dutch for “object”), is an intergalactic oddity. Around 100,000 light years across, it is the visible part of a 300,000-light-year-long twisting rope of gas that wraps around the nearby spiral galaxy IC 2497. The galaxy is a former quasar, and the Vorwerp appears to have been lit up by the quasar’s light. In this Hubble image, the Vorwerp is coloured green, signalling the presence of ionized oxygen. Star formation is taking place on the side of the Vorwerp facing the galaxy. Both the Vorwerp and IC 2497 are 650 million light years away. More at Bad Astronomy and the HubbleSite. Credit: NASA, ESA, W. Keel (University of Alabama), and the Galaxy Zoo Team.
A false-colour image of sand dunes on the floor of Arkhangelsky Crater in Mars’s southern hemisphere, taken by the Mars Reconnaissance Orbiter's HiRISE camera. Near-infrared, red, and blue-green filters have been mapped to red, blue and green channels, respectively. Credit: NASA/JPL/University of Arizona.
Question: Which of these two moons is larger, and which of them is further away? Answer: Dione (top right) is both larger and further away than Enceladus (bottom left). Dione is twice the diameter of Enceladus (1123 km vs. 504 km), and from Cassini’s vantage point in this image acquired on December 1, 2010, Dione is 830,000 km away, versus Enceladus’s 510,000 km. Bad Astronomy, Universe Today. Credit: NASA/JPL/Space Science Institute.
The Crab Nebula in X-ray — here in an image from the Chandra X-Ray Observatory — looks nothing like it does in visible light. Astronomers considered the Crab’s X-ray emissions so stable that they calibrated their instruments by it; recent observations, however, suggest a decline of several percentage points. Credit: NASA/CXC/SAO/F.
Spiral galaxy NGC 1345, about 85 million light years away in Eridanus, as captured by the Hubble Space Telescope’s Advanced Camera for Surveys through blue and near-infrared filters. (Infrared light is red in this image.) Look closely and you’ll see even more distant galaxies, tiny and reddish, surrounding NGC 1345. Credit: ESA/Hubble & NASA.