Why are the transits of Venus so rare? The orbit of Venus is inclined 3,4 degrees relative to the orbit of the Earth. Venus usually passes below or above the Sun when passing between the Earth and the Sun. A transit is only possible when Venus is situated close to the point of interception with the orbit of the Earth.

The blackest object we have observed: During the transit Venus waw blackest object that we have ever seen! The night side of Venus is not emitting visible light. The contrast to the very bright solar disk was extreme!

Brief facts about Venus

• Diameter: 12 104 kilometers (94,9 % of Earth)
• Distance from the Sun: 108.2 million km
• Smallest distance from the Earth: Less than 40 million km
• Eccentricity of orbit: 0.0068 (orbit of Earth: 0.017)
• Inclination: 3.39 degrees
• Average surface temperature: 464 degrees Celsius
• Atmosphere: Very dense, pressure of 90 atmospheres at surface
• Chemical composition of atmosphere: 96.5% CO2, 3.5% N2, 0.003% water vapour
• Day length: 243.01 days (retrograd rotation)
• Inclination of rotation axis relative to orbit: 177.4 degrees
• Length of year: 224.70 days
• Age of surface: About 800 million years
• Mean density: 5.243 times density of water (density of the Earth is 5.515)
• Mass: 4,869 * 1024 kgs = 0,815 times mass of the Earth
• Average velocity in orbit: 35 km/s = 126 000 km/h

In the early afternoon the Moon started to enter the shadow cast by our planet. Even during the total phase some sunlight reached the Moon. The Moon therefore did not disappear from sight, but had a beautiful, red color. This is due to sunlight that passes through the atmosphere on the Earth. This happens where the Sun is setting or rising. The color of both the atmosphere and the eclipsed Moon reflects this.

If we had been situated on the Moon during the eclipse we would experience a total solar eclipse. The completely black night side of the Earth would be surrounded by a thin, red ring – the atmosphere.

The eclipse was total from 15.06 – 15.57 MET / local Norwegian time. For about one hour before and after the totality spectacular partial phases was visible when the Moon moves into and out of the shadow.

Links:

• More information (astroevents.no)
• Press release from NASA
• NASA home page for this event

Underneath you can watch images from our webcast december 10.

It was possible to witness the close passage with amateur telescopes. 2005 Yu55 was closest at 00.28 MET on November 9, 2011. Its closes position to the Moon was 239 000 kilometers at 08.13 MET the same day.

It is not that rare that this asteroid comes close to the Earth, but it was at least 200 years since the last time it came this close. The velocity relative to us was 49 300 km/h.

The last time we know that such a large asteroid has come this close was in 1976. The next visit of this kind til take place in 2029 when 2001 WN5 is 0,6 lunar distances from Earth and in 2029 Apophis will be less than 30 000 kilometers from the surface of the Earth!

Lenker:

• Mer info (astroevents.no)
• Pressemelding fra NASA
• Søkekart fra Trondheim Astronomiske Forening

Underneath you can watch archived images from our live webcast.

Total lunar eclipses occurs when the Moon is crossing the shadow cast by the Earth. Some light from the Sun penetrates the atmosphere of the Earth and is scattered onto the Moon giving it the (usually) red color. From the surface of the Moon we would have experienced a total solar eclipse.

Links:

• More information (astroevents.no)
• Video of how a lunar eclipse works (nasa.gov)
• Path of the Moon through the penumbra and umbra as well as a map of Earth showing the regions of eclipse visibility - PDF (nasa.gov)

Underneath you can watch archived images from our live webcast.

It might sound like a contradiction to have a solar eclipse in the middle of the night. But this was what happened in northern Norway, Sweden and Finland on June 1. Almost 60 % of the Sun was hidden by the Moon around midnight local time. A midnight Sun eclipse can only occur close to the poles and only during summer when the Sun never sets.

From time to time partial solar eclipses occur around the globe. When views through eclipse shades these eclipses can be quite beautiful. During large solar eclipses it becomes darker, and the light silvery. This time the beautiful reddish and yellow colors in the sky caused by the midnight Sun mixed with the effects of a 60 % (diameter) solar eclipse.

In Norway the eclipse began at 22:37 local time (20:37 UT) and ended at 00:22 (22:22 UT). Maximum eclipse was reached around 23:30 local time (21:30 UT).

The eclipse could be viewed from the Norwegian counties of Møre og Romsdal, Trøndelag, Nordland, Troms, Finnmark as well as Spitsbergen. Northern Norway and Spitsbergen enjoyed the best view.

Since the rotational axis of the Earth is tilted by 23.5 degrees areas located north of 67.5 degrees latitude (the Arctic Circle) experience a period each summer when the Sun does not set – it is a midnight Sun.

Links:

• Local times and conditions (astroevents.no)
• Visibility for the eclipse - PDF (nasa.gov)
• More information (astroevents.no)

Underneath you can watch archived images from our live webcast.