The Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment, or HiRISE, captured this view of a recent impact crater on the Red Planet. According to a NASA description, “the new crater and its ejecta have distinctive color patterns. Once the colors have faded in a few decades, this new crater will still be distinctive compared to the secondaries by having a deeper cavity compared to its diameter.” North is up.
All five of the bright naked-eye planets are observable in the pre-dawn sky from about the third week of January 2016, particularly if one lives south of the equator. But even from the UK, you can get to view the spectacle if you time it right — and the weather obliges! The last time that Mercury, Venus, Mars, Jupiter and Saturn appeared in the same sky was 11 years ago.
Vast valley networks on Mars have suggested that water may have flowed there for millions of years. Now a study at Brown University suggests the valleys could have been carved by much less water in as little as a few hundred to 10,000 years. The findings are consistent with the idea that early Mars may have been cold and icy, with surface water flowing sporadically in response to short-term climate changes.