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Venus Transit And Lunar Mirror Could Help Astronomers Find Worlds Around Other Stars

December 19, 2012 Leave a comment

When Venus passes in front of the Sun it hides a part of our star’s rotating surface. Because of rotation, the spectrum of the Sun (created splitting the different colours of light using a spectrograph) is slightly different on each side. On one side, the solar surface is rotating towards the observer and so its light will be ‘blueshifted’, meaning the lines seen in a spectrum move towards shorter wavelengths. On the other, the surface is rotating away from the observer, so its light is ‘redshifted’, meaning that the lines move towards longer wavelengths.

By looking at the reflected light from the lunar surface, this is averaged out as a broadening of the various lines. When Venus moves in front of the Sun from east to west, it first blocks out the surface moving towards us and then the surface moving away from us. This causes a distortion in the spectral lines known as the “Rossiter-McLaughlin effect”.

The astronomers realised that the High Accuracy Radial Velocity Planet Searcher (HARPS) spectrograph installed on a 3.6m telescope at La Silla in Chile, part of the European Southern Observatory (ESO), would be sensitive enough to detect the effect and that the Moon would be in the right place too. The Moon was slightly ahead of the Earth in its orbit, so ‘saw’ the transit a couple of hours later than terrestrial observers. This also meant that the Moon was in the night time sky in Chile, making it possible for the La Silla telescope to operate safely and observe the change in the solar spectrum.

Full Story: http://www.ras.org.uk/news-and-press/219-news-2012/2203-venus-transit-and-lunar-mirror-help-astronomers-find-worlds-around-other-stars

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Cook’s View Of The Transit Of Venus


Exactly 243 years ago, Captain James Cook made the sketch you see above. On June 5–6, 2012, you could make your own drawing of such a rare celestial event (provided you have the right eye-protecting equipment). But don’t miss the chance, as you won’t get another one for 115 years.

Cook’s drawing shows the Transit of Venus as it appeared on June 3, 1769, from Tahiti. During first voyage around the world, Cook, astronomer Charles Green, and the crew of the HMS Endeavour set up observing equipment on what is now known as Point Venus. In fact, the Transit was one of the motivations for the expedition, as it would provide valuable information for determining the size of our solar system. The explorers made many measurements of the event, and Green added his own sketch (see the downloadable large image).

Full Story: http://earthobservatory.nasa.gov/IOTD/view.php?id=78158&src=eoa-iotd

SDO’s Ultra-High Definition View Of 2012 Venus Transit


On June 5 2012, the Solar Dynamics Observatory (SDO) collected images of the rarest predictable solar event — the transit of Venus across the face of the sun. This event lasted approximately 6 hours and happens in pairs eight years apart, which are separated from each other by 105 or 121 years. The last transit was in 2004 and the next will not happen until 2117.

YouTube: http://www.youtube.com/watch?v=4Z9rM8ChTjY
SVS (Broadcast quality): http://svs.gsfc.nasa.gov/vis/a010000/a010900/a010996/index.html

Last Chance For A Century To Witness The Transit Of Venus


For the last time until the year 2117, people around the world will have a chance to witness the transit of Venus as the planet passes directly between Earth and the Sun on Tuesday 5th June and Wednesday 6th June. The event will appear as a tiny black disk creeping across the Sun’s face. Events are taking place for people to safely view this event and telescopes and space satellites will have the best seats to get close up details.

NASA’s Solar Dynamics Observatory, in orbit around the Earth, is scheduled to provide the best possible views of the event, producing the highest resolution, most detailed images ever taken of the Sun during a transit. RAL Space (based at STFC’s Rutherford Appleton Laboratory) not only provided electronics systems for the satellite’s cutting-edge cameras but is also a co-investigator on the mission.

A key aim of scientists’ observations will be to help develop and refine techniques for discovering and characterising planets beyond our solar system by observing them as they pass across the faces of their parent stars.

Full Story: http://www.stfc.ac.uk/News+and+Events/39127.aspx

Venus, A Planetary Portrait Of Inner Beauty


A Venus transit across the face of the sun is a relatively rare event — occurring in pairs with more than a century separating each pair. There have been all of 53 transits of Venus across the sun between 2000 B.C. and the last one in 2004. On Wednesday, June 6 (Tuesday, June 5 from the Western Hemisphere), Earth gets another shot at it – and the last for a good long while. But beyond this uniquely celestial oddity, why has Venus been an object worthy of ogling for hundreds of centuries?

“Venus is a fascinating yet horrendously extreme place all at once,” said Sue Smrekar, a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Although the surface is hot enough to melt lead due to its runaway greenhouse atmosphere, in many respects it is Earth’s twin [size, gravity and bulk composition].”

Full Story: http://www.jpl.nasa.gov/news/news.cfm?release=2012-150

Astronomers Without Borders To Webcast Transit Of Venus From Mount Wilson Observatory


As Venus crosses the face of the Sun on 5/6 June for the last time in this century, Astronomers Without Borders will stream the event live to a worldwide audience from historic Mount Wilson Observatory in Southern California. With experts, authors, and astronomers on hand, and vintage telescopes alongside modern ones, there will be plenty to see and learn about this very rare event and its importance to historical efforts to understand our solar system.

Only six transits of Venus have been observed since the invention of the telescope more than 400 years ago. There were no transits of Venus from 1882 to 2004, and the next one won’t take place until 2117.

In the 18th and 19th centuries, scientific expeditions sailed around the world to observe transits of Venus from widely separated locations in an attempt to measure the distance from Earth to the Sun. This basic unit of measure for distance in the solar system is now known with great precision. But transits of Venus provide 21st century astronomers with ways to test their methods for discovering and exploring planets circling distant stars. These unseen planets sometimes cross in front of their stars, slightly dimming the star’s light, in an event known as an “exoplanet transit.”

Full Story: http://www.astronomerswithoutborders.org/projects/transit-of-venus/live-webcast.html

Astronomers Without Borders And Partners Bring Phone And Online Technology To The Transit Of Venus


Astronomers Without Borders has partnered with the Venus Transit Project and Esri, a leading geographic information systems company, to create unique smartphone and web apps for the transit of Venus.

Owners of mobile devices using the Apple and Android operating systems can now take part in the largest such effort ever thanks to a new free app developed by Steven van Roode of the Transit of Venus Project. Anyone can emulate the expeditions of old without leaving home or making lengthy measurements of their location or local time.

Just a few clicks on a smartphone is enough, and many thousands are expected to join in. The technology used was not available even for the Venus transit in 2004 — the only other transit to occur since the 19th century — ensuring that this project will see unprecedented participation.

For Apps: http://www.astronomerswithoutborders.org/news/newsletters/latest-newsletter.html