Space Photos of the Day (and Commentary)

Absolutely Amazing: ISS, Discovery Transit Sun Near Active Sunspot Region. "Amateur astronomer Catalin Fus from Poland has captured one of the most amazing images I’ve ever seen – and his timing was impeccable. On March 7th at 13:05:49 UTC, just after space shuttle Discovery had undocked from the International Space Station, the two ships flew in formation directly in front of the Sun, as seen from Fus’ location just outside of Krakow. With his solar-filtered telescope focused on active sunspot region 1166, he found there were a couple extra spots in his image – Discovery and the ISS. Given that this was Discovery’s final mission in space and final visit to the ISS, this image has historical significance, as well as just being absolutely fantastic. Keep in mind that transits like this last just over a half a second."

New Color Image Shows Opportunity Rover from Orbit "Another great shot by the HiRISE camera on the Mars Reconnaissance Orbiter: this one of the Opportunity rover sitting on the edge of Santa Maria Crater. The High Resolution Imaging Science Experiment took this image on March 1, 2011, and also visible are the tracks in the Martian soil that Oppy created as she made her way to the crater."

‘Armada of Telescopes’ Captures Most Distant Galaxy Cluster Ever Seen. "The international team of astronomers used the powerful VIMOS and FORS2 instruments on ESO’s Very Large Telescope (VLT) to measure the distances to some of the blobs in a curious patch of very faint red objects first observed with the Spitzer space telescope. This grouping, named CL J1449+0856  for its position in the sky, had all the hallmarks of being a very remote cluster of galaxies. The results showed that we are indeed seeing a galaxy cluster as it was when the Universe was about three billion years old.

Once the team knew the distance to this very rare object, they looked carefully at the component galaxies using both Hubble and ground-based telescopes, including the VLT. They found evidence suggesting that most of the galaxies in the cluster were not forming stars, but were composed of stars that were already about one billion years old. This makes the cluster a mature object, similar in mass to the Virgo Cluster, the nearest rich galaxy cluster to the Milky Way."