Gaze upon all of Mercury for the first time ever


The existence of our solar system's innermost planet has been common knowledge since ancient times, but that doesn't actually mean we've always know much about it. Mercury's proximity to the Sun has allowed it to jealously guard its secrets, and so this NASA video offers an unprecedentedly detailed view of the planet's surface.

This video is based on images taken by the MESSENGER probe, the first spacecraft to actually orbit Mercury. It has allowed astronomers to get the first up-close view at the planet's geology; until now, the sum total of our knowledge was limited to a single Mariner flyby in 1975. Over the past year, MESSENGER has taken over 80,000 images with plans to take 80,000 more. That's allowed us to assemble this complete visual representation of Mercury's surface, with each pixel representing about a square kilometer; the video expands on this previously published image.

Written By: Alasdair Wilkins
continue to source article at


  1. In reply to #1 by aroundtown:

    I do wonder about the thermal imaging that has been applied

    Many satellite multispectral images use false colours.

    One day there may be a much better view, like when a landing occurs

    That would have to be a seriously designed piece of kit to cope with the range of temperatures on Mercury, unless a landing site was picked very carefully.

    Because it has almost no atmosphere to retain heat, Mercury’s surface experiences the greatest temperature variation of all the planets, ranging from 100 K (−173 °C; −280 °F) at night to 700 K (427 °C; 800 °F) during the day at some equatorial regions. The poles are constantly below 180 K (−93 °C; −136 °F).

  2. may look to the human eye like Earth’s moon…

    Nah, looks like a planet – “crazy ’bout a Mercury”!

    Was excited when I saw this on APOD; MESSENGER’s close-by surveillance paid off big time 🙂

  3. In reply to #4 by aroundtown:

    Those are some amazing temperature ranges. Great place to verify the absolute zero theory huh.

    For absolute zero it is probably better to use satellites with sun shades and a cryostat, or to go to the outer Solar-System, where the gear is not alternately fried and frozen!

    Spitzer is designed to look at faint heat radiation from objects in space. In order to be able to do this, the instruments on board must be kept very cold so that their own heat does not interfere with the observations. Spitzer carries a “cryostat”, which uses liquid helium vapor from the helium tank to keep the instruments cold. The cryostat holds about 360 liters of liquid helium, and can cool the instruments to temperatures as low as 1.4 degrees Kelvin (roughly -457 degrees Fahrenheit, or -272 degrees Celsius) for more than 5 years.

    The cryostat is attached to the bottom of the telescope, and consists of the helium tank, a vacuum shell, inner and middle vapor-cooled shields and a fluid management system. The telescope and the cryostat shell were launched warm, and cooled down to about 35 degrees Kelvin once they were in orbit. The cryostat vacuum shell was sealed during ground operations and launch, and kept closed as the telescope cooled in order to protect the delicate instruments. Once the cryostat had cooled, a door on the top of the shell was opened to allow light into the Multiple Instrument Chamber.

Leave a Reply