Lutetia at closest approach

10 July 2010

The European Space Agencies (ESA) space probe Rosetta executed its flyby of asteroid Lutetia a few hours ago.

Here is the image taken at closest approach.

Lutetia’s name is derived from the Latin name for Paris. It is roughly 100 km large.

Rosetta is named after the Rosetta stone. Rosetta passed by asteroid Steins 5th September 2008.

Noctilucent clouds – revisited

9 July 2010

A couple of days ago we have had a fine sunset with noctilucent clouds.

So what is so interesting about noctilucent clouds?.

First of all they are clouds made of ice crystals that are extremely high up (75-85 km according to wikipedia). They can only be seen around twilight since they are then illuminated from underneath by the Sun that has already set. They are mostly seen from highish latitudes (50-70 degrees – I am at around sixty degrees). They are fairly uncommon.

Revisited because of my previous (failed) attempt to capture noctilucent clouds.