Posted in Astronomy at 12:00 on 26 November 2014
A movie showing liquid on the surface of a world other than Earth?
Yes indeed. This is Saturn’s moon Titan and its methane/ethane lakes in a digital compilation of still radar images from NASA’s Cassinni satellite. The liquid is deep blue, the higher land tan coloured.
The video featured on Astronomy Picture of the Day on 24/11/14.
Posted in Astronomy at 19:52 on 14 July 2011
I see from Astronomy Picture of the Day that Neptune is now one (Neptunian) year old.
Source: Hubblesite.org.
The four images are of Neptune at four hour intervals. Neptune rotates once in 16 hours and so they show one whole Neptunian day. The white stuff is cloud. The clouds contain methane crystals, rather than water ice.
The planet was discovered on September 23rd, 1846 by German astronomer Johann Galle. Since its orbit takes 165 and a bit (Earth) years, this week on July 12, Neptune has completed one revolution around the Sun since its discovery date.
Many happy returns.
