Astronomy news

Update on Comet Elenin

NASA (see www.jpl.nasa.gov/news/news.cfm?release=2011-135?cid=release_2011-135 ) has issued a news release on Comet Elenin - and its progress from the outer reaches of space on its journey towards the inner solar system. It is now 170 million miles away and so far it has been a bit of a wimp - according to NASA spokesman Don Yeomans. Even at its closest point observers may require the use of binoculars - and a clear sky. However, we have until October 16th for things to change - when it will be 22 million miles away.

NASA electricity in space video

At www.jpl.nasa.gov/news/ on April 20th, NASA is releasing the first images and sounds of an electrical connection between Saturn and one of its moons, Enceladus - as collated by the Cassini spacecraft. An analysis of the data will be published in Nature but to see the video with sound go to www.nasa.gov/cassini or http://saturn.jpl.nasa.gov/video (click on Saturn and Enceladus electrical link video)

Draco

At www.unreportedheritagenews.com/2011/04/rising-above-acropolis-constellat... some computer retrocalculation software of the sky at night has shown that the constellation Draco, the dragon, would have been above the acropolis and its temple in mid first millennium BC. This is when Athens was at its apogee and people celebrated the birth of Athena with festivities and athletic games and contests. Astronomy may have been a part of the process, it is hypothesized, and Draco was highly visible one or two hours after sunset, it seems.

Solar cycle 24 is gathering pace ... and invisible cosmic objects

NASA is saying solar cycle 24 is finally on (see http://wattsupwiththat.com/2011/04/15/watched-solar-cmes-never-boil/ ). In 2008 sun spots disappeared and flares subsided and there was lots of ink spent on the quiet Sun. Three years later and the Sun has rumbled back into life - and aurora are being seen across the top of the world once again. 

Luni-solar influences and the length of the day

At http://wattsupwiththat.com/2011/04/10/solar-terrestrial-lunisolar-compon... by Paul Vaughn, M.Sc. It is about a French paper on solar cycles and the rate of change of the length of day, by Courtillot et al (2010). Variations in the length of day involve the lunar nodal cycle (18.6 days), the lunar apse cycle (8.85 years), the terrestrial year (1 year) and harmonics (0.5 and 4.42 yrs). See also http://wattsupwiththat.com/2010/12/23/confirmation-of-solar-forcing-of-t...

Another close shave

At www.physorg.com/print221392528.html there is a report from Spaceweather.com that said two small asteroids came close to earth on April 6th - half the distance of the Moon. They were 10km and 6km wide respectively - and there are more on the way later in the year.

Comet Wild2

NASA and JPL Caltech say they have found the presence of liquid water in Comet Wild2 - but comets are supposed to be so cold they never get warm enough to melt ice. Some clever jiggery pokery is theorised - the process happens 'inside' the comet. If it was cold on the outside it may not be so cold on the inside - yet comets are supposed to originate in the outer solar system where it is thought to be very cold indeed. According to a spokesperson there are two ways to generate a heat source on a comet. A collision or radioactive decay of elements in the comet interior.

Gravity and the earth ... and the Sun.

Some exciting science at www.bbc.co.uk/news/science-environment-12911806?print=true ... GOCE, the Gravity Field and Steady-State Ocean Circulation Explorer, is onboard a satellite launched in 2009 and moves around the earth from pole to pole at an altitude of 255km. It is able to map the very small differences in pull exerted by the mass of the planet from one region to the next - from mountains to ocean trenches. It can calculate gravity at any given point that it observes.

The Planet Mercury

NASAs Messenger spacecraft is now in orbit around Mercury and has returned the first image of the planet. Altogether some 360 + images have been taken by NASA and these will be released later in the week. See www.sciencenews.org/view/genric/id/71951/title/First_portrait_of_Mercury...

Einstein

At www.dailygalaxy.com/my_weblog/2011/03/could-space-time-be-a-mirage-new-t... there is a story about gravity and relativity and variations as advanced by Peter Herova that eliminates dark matter and dark energy by adjusting Einstein. In contrast, at www.physorg.com/print220174620.html where it claims Einstein's theory fights off challengers.