Mars may have an ugly history – giant tsunamis, blistering solar wind, robot invasions – but it's looking pretty good in this new photo from the Hubble. This month, the planet comes closer to our own than it has for over a decade, and on May 12 the Hubble took full advantage and captured a shot from just 50 million miles away.
The resulting image – shown in natural color – reveals details as small as 20 miles across.
It's not just the close proximity that makes this image so sharp. If you've ever tried your hand at photography, you know that the best way to light a photo is to stand with the Sun behind you. This month, Mars is approaching something called "opposition." When it reaches opposition on May 22, our planets will be perfectly aligned with the Sun, because their orbits will catch up with one another: The Sun and Mars will be on exact opposite sides of Earth. Since Hubble is basically on Earth, cosmically speaking (it's in a low orbit), that means our "photographer" is perfectly positioned with the Sun behind her and her subject (Mars) straight ahead. Everything is illuminated.
That giant orange splotch is called Arabia Terra, and it stretches over 2,800 miles of the planet. Scientists believe that it might be one of the oldest areas on the planet, because it's densely cratered. Geologic activity like volcanic explosions smooth out planetary surfaces, so an abundance of craters says as much about how "dead" a planet is as it does about the world's role as a cosmic punching bag. Dark features running along the planet's equator are colored by the bedrock and sand of ancient lava flows.
To the far right, you can spot Syrtis Major – an ancient, inactive shield volcano – surrounded by clouds. Just south of that is an oval crater called the Hellas Planitia basin – the largest crater on the planet, more than 1,000 miles across – which was formed by an asteroid 3.5 billion years ago. The crater is nearly five miles deep.
Mars and Earth line up around the Sun this way as often as once every two years or so (every 780 days, to be precise). But because Mars has an elliptical orbit, not all of these oppositions are made equal. On May 30, eight days after its moment of perfect alignment, Mars will be just 46.8 million miles away from Earth – its closest approach in 11 years.