News

MESSENGER data reveals great valley on Mercury

Scientists have discovered a 600-mile-long valley on Mercury that may be the first evidence of buckling of the planet’s outer silicate shell in response to global contraction. The researchers discovered the valley using a new high-resolution topographic map of part of Mercury’s southern hemisphere created by stereo images from NASA’s MESSENGER spacecraft.

News

Shrinking Mercury is tectonically active

Images from NASA’s MESSENGER spacecraft reveal previously undetected cliff-like landforms on Mercury that scientists believe must be geologically young, which means that the innermost planet is still contracting and that Earth is not the only tectonically active planet in our solar system, as previously thought.

Observing

See Mercury at its best in the east at dawn

Mercury is currently putting on a fine show in the east before dawn. Find a UK location with an unobstructed view due east an hour before sunrise to see the innermost planet some 6 degrees above the horizon from about 25 September—5 October. The very old crescent Moon lies just 2 degrees from Mercury at dawn on Thursday, 29 September.

Observing

Jupiter and Venus get extra close in the evening sky

On Saturday 27 August at 22:32 UT (11:32pm BST), a spectacularly close conjunction occurs between Jupiter and Venus just 22 degrees west of the Sun in the constellation of Virgo, when the planetary pair are just 4 arcminutes, or one-fifteenth of a degree, apart. Here is our guide to the best locations and times to view this rare event.

Picture This

Mercury and International Space Station transit the Sun

French astrophotographer Thierry Legault travelled to the suburbs of Philadelphia, USA to capture both the International Space Station and planet Mercury transiting the Sun on 9 May. This image includes multiple stacked frames to show the Station’s path in the fraction of a second it took to cross the Sun, while Mercury appears as a black dot at bottom-centre.