Mercury

Seared by a Sun shining ten times stronger than it does at Earth, Mercury is a burnt-out cinder, a roasted Moon-like world -- or is it? NASA's MESSENGER mission, the first orbiter of the smallest planet, has revealed a tumultuous volcanic past, enigmatic recent "hollows," and a dynamic exosphere. And it's chasing after clues from Earth-based radar surveys that Mercury could be hiding water ice in permanently shadowed craters near its poles.

Recent Blog Articles About Mercury

Planetary Society Weekly Hangout (Special Time): MESSENGER at Mercury with Larry Nittler, Fri May 3 5pm PDT / midnight UTC

Posted by Emily Lakdawalla on 2013/05/02 07:00 CDT | 2 comments

Note the special time! In this week's Planetary Society hangout at 5pm PDT / midnight UTC, I'll talk with MESSENGER deputy principal investigator Larry Nittler about what MESSENGER has accomplished in its prime and extended missions at Mercury, and what it stands to do if awarded a mission extension.

One Day in the Solar System

Posted by Bill Dunford on 2013/04/08 09:12 CDT | 4 comments

Dispatches from five different worlds--all sent by robotic spacecraft on the same day.

Permanently shadowed, radar-bright regions on Mercury

LPSC 2013: Seeing in Permanent Shadow

Posted by Michael Poston on 2013/04/03 01:21 CDT | 1 comments

The case for water ice hidden in permanently shadowed regions at the north pole of the planet Mercury received another boost recently. On Wednesday March 20, 2013 at the Lunar and Planetary Science Conference, Nancy Chabot presented the very first visible-light images of what is in the shadows of these polar craters.

LPSC 2013: Do we have a meteorite from Mercury?

Posted by Emily Lakdawalla on 2013/03/21 06:14 CDT | 7 comments

Before yesterday, my answer to this question would be "no." Now my answer is "probably." But it's not clear if we know which of the meteorites in our collections is from the innermost planet.

Messages of Wonder

Posted by Bill Dunford on 2013/03/18 04:22 CDT

Some lovely, rarely-seen images from the MESSENGER mission.

Water ice and organics at Mercury's poles

Posted by Emily Lakdawalla on 2012/11/29 02:16 CST | 9 comments

Water ice at Mercury's poles? That's crazy, right? The MESSENGER team has made a very good case that radar-bright material seen by the Arecibo telescope is, in fact, water ice, covered in most places by a veneer of dark organic material.

Full Free Intro Astronomy Class Now Online

Posted by Bruce Betts on 2012/05/22 02:57 CDT

Bruce Betts' complete CSUDH Intro Astronomy and Planetary Science class is now available online. Find out how to access it, and go behind the scenes.

Notes from the Lunar and Planetary Science Conference: Is there ice at Mercury's poles?

Posted by Emily Lakdawalla on 2012/03/22 10:28 CDT

Water ice at Mercury's poles? That's crazy, right? Mercury is so close to the Sun that it seems inconceivable that you could have water ice there. But Mercury's rotational axis has virtually no tilt (MESSENGER has measured its tilt to be less than 1 degree), so there are areas at Mercury's poles, most often (but not always) within polar craters, where the Sun never rises above the horizon to heat the surface.

Notes from Day 3 of the EPSC/DPS meeting (all about MESSENGER)

Posted by Emily Lakdawalla on 2011/10/05 11:04 CDT

Notes from Day 3 of the EPSC/DPS meeting (all about MESSENGER)

Mercury's Weird Terrain

Posted by Emily Lakdawalla on 2011/04/19 11:21 CDT

When Mariner 10 flew past Mercury, it caught an immense impact basin lying half in and half out of sunlight, which they named Caloris. Even with only half the basin visible, scientists knew it was one of the largest in the solar system. Geologists had to wait more than 25 years to see the rest of Caloris, and when they did it turned out to be even bigger than they had thought. But the fact that Caloris was only half in sunlight was fortuitous in one sense, because it meant that the spot on Mercury that was exactly opposite the area of the Caloris impact was also partially in sunlight. That spot looks weird.