Venus 12 Days After Transit ImageSouce CCD and 16 inch Ritchey–Chrétien telescope. 3 min video processed with Registax software. (Credit & Copyright: Dean Salman / National Optical Astronomy Observatoroes (NOAO) / Association of Universities for Research in Astronomy, Inc.)
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Venus 12 Days After Transit

ImageSouce CCD and 16 inch Ritchey–Chrétien telescope. 3 min video processed with Registax software.

(Credit & Copyright: Dean Salman / National Optical Astronomy Observatoroes (NOAO) / Association of Universities for Research in Astronomy, Inc.)

Venus Transit in hydrogen alpha light, 5 June 2012 (Credit & copyright: Gilbert A. Esquerdo)
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Venus Transit in hydrogen alpha light, 5 June 2012

(Credit & copyright: Gilbert A. Esquerdo)

After the transit of Venus, what next?

Venus has transited the sun and we must now wait 105 years before the next time. But Keith Cooper, editor of Astronomy Now, says there are other rare astronomical spectacles to look out for sooner than that. So what’s the next big event in the sky?

(Venus begins to cross the Sun’s face during the transit of Venus as seen from the west side of Manhattan in New York. Credit: Stan Honda/AFP/Getty Images)

9 May 2016: Transit of Mercury

Far less rare than a transit of Venus – there will be another in 2019 – but still something that the world’s astronomers will ready their telescopes for.

2 August 2027: Solar eclipse

Solar eclipses are one of the great natural wonders and one can usually be seen somewhere on Earth each year. But the one in 2027 will be exceptionally long with a maximum duration of six minutes and 23 seconds. It will pass through the Straits of Gibraltar then across the North African coast before dipping down to Yemen and Somalia.

2029: Near-earth asteroid fly-by

A 270-metre-wide asteroid called 99942 Apophis will pass between the moon and Earth. The chances of a collision with Earth have largely been ruled out, but astronomers will be keen to see if the Earth’s gravity will “perturb” its course and thereby increase the chances of a collision the next time it passes in 2036 – on April, Friday the 13th.

July 2061: Return of Halley’s Comet

The famous comet was last seen with the naked eye in 1986 and it is next “perihelion” (closest point of orbit to the Earth) is predicted to be in the summer of 2061 for a few weeks as it travels through the inner solar system.

22 November 2065: Venus occults Jupiter

For the first time since 1818, a planet will appear from Earth to pass directly before another planet. They will briefly look to have formed into a single, bright star low down in the dawn skyline.

10 November 2084: Transit of Earth as seen from Mars

It will be the first and only time this will occur this century, with the next one predicted for 2394. Something for the first colonists of Mars to look forward to.

Could happen any time: Supernova in our galaxy

The last time a star exploded in our galaxy was 408 years ago. But, on average, they should occur twice every century, so one is more than overdue…

(Editor’s note: this story, from the UK’s Guardian, was largely intended for European audiences.  As a result, they missed the upcoming total solar eclipse of 21 August 2017, the first total eclipse visible from the mainland U.S. in nearly 40 years! -JCB)

Transit Of Venus 5 June 2012 Seen in projection at the UW Space Place, Madison, WI
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Transit Of Venus 5 June 2012

Seen in projection at the UW Space Place, Madison, WI

5 June 2012 Venus transit from Solar Dynamics Observatory (SDO)
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5 June 2012 Venus transit from Solar Dynamics Observatory (SDO)

View Today’s Venus Transit Online

So you say it’s cloudy where you live today, or you don’t have the proper eye protection required to see the event, but you still want to see the historic Venus Transit? 

The Interwebz are here to save you.  

A number of online resources are available, including telescopes broadcasting live feeds of the event:

Also, during the transit, check out what space-based observatories are seeing:
Enjoy!

(with thanks to Professor Astronomy and Sky & Telescope for the links)

The Disappearing Black Drop

Observers of historical transits of Venus have observed the black drop effect — but will you?

(This series of images shot from Singapore shows the possibility of a black-drop effect.  Credit: Joseph Tey)

“After the 2004 transit of Venus, observers were puzzled by the appearance (or lack thereof) of the black-drop effect, the dark patch that appears to connect Venus with the dark sky past the edge of the Sun, sometimes giving Venus a teardrop shape. The black drop was widely observed and commented on in the 18th and 19th centuries. So why, in 2004, did some people not see it at all?”

“‘Some of it may be a matter of degree,’ says Jay Pasachoff (Williams College). He says his study with Glenn Schneider (University of Arizona) of space-based images of the 1999 and 2003 Mercury transits shows that the telescope’s optics and resolving power are a factor in the black-drop effect. But they discovered that the Sun’s limb darkening— the fact that the Sun’s edge is darker than its center — is another important contributor. ‘So it’s not a surprise that big telescopes that have a better point-spread function don’t show a black drop effect.’”

(The ‘black drop effect’ — an unexpected “neck” of darkness that seems to connect the black sky to the disc of either Venus or Mercury during solar transits — was at times attributed to everything from refraction of light in the atmospheres of those planets to the imagination of observers’ minds.  Now we know that at least the effect is real, but it is the result of several factors conspiring together, including imperfections in the way telescopes image light.  What will telescopic observers see on Tuesday? -JCB)

(Australian watchmaker F. Allerding recorded the “black-drop” effect as the silhouette of Venus prepared to exit the Sun’s disk on December 9, 1874. He observed through a 3½-inch refractor.  CredIt: Institute for Astronomy, Univ. of Vienna.)

Your Viewing Guide to the Transit of Venus

A literal once-in-a-lifetime event occurs this Tuesday, when the silhouette of the planet Venus crosses the visible face of the Sun over several hours.  Here’s when and where to see it.

What can you expect to see?

“Venus will take about 6 hours 30 minutes to cross the northern side of the Sun. The line is plotted as seen from Earth’s center. Universal Times (also geocentric) are given for the event’s four contacts: I and II as Venus moves onto the Sun (called ingress), III and IV as it leaves (egress) and for Venus’s deepest encroachment onto the solar disk.”  (Credit: Leah Tiscione/Sky & Telescope)

Where will the transit be visible?

“For most of North America, the transit of Venus will begin on the afternoon of June 5th and still be in progress at sunset. Those in western Pacific, eastern Asia, and eastern Australia see the whole show from beginning to end on June 6th (local date). Click here for a larger, worldwide map.” (Credit: Michael Zeiler / Eclipse-maps.com)

How’s the weather going to be?

“Based on statistical averages of daytime clouds during June, the American Southwest, northern Australia, and the Middle East offer the best chances of clear skies for the transit of Venus. Click here for a larger version.”  (Credit: Jay Anderson)

Why does it matter where on the Earth one is located?

“Your location north or south on Earth slightly affects the apparent path you see Venus taking south or north across the Sun. In 1716, Edmond Halley realized that measurements of this offset, done by timing Venus’s contacts with the Sun’s edges, could be used to determine Venus’s parallax as seen from Earth and hence the distance to both Venus and the Sun. That in turn would give the correct scale of the entire solar system, which was poorly known at the time.”  (Credit: Sky & Telescope)

PLEASE READ this summary of safe solar viewing tips and protect your eyes!

Transits Of Venus Through History

1. “The ancient Babylonian Venus Tables of Ammizaduga contains information about the movements of Venus, but mentions no transit, though the Babylonians had opportunity to see ones in 1512, 1520, and 1641 BC.”

2. “English astronomer Jeremiah Horrocks is considered the first human to have witnessed a Venus transit. He concluded that existing information about planetary positions was incorrect, so he gathered his own data, allowing him to correctly predict a transit of Venus in 1639 (which Kepler had not foreseen).”

3. “On June 5, 1761 the transit of Venus was observed by 176 scientists positioned all over the world. Russian astronomer Mikhail Lomonosov noticed a halo of light that surrounded the disk of Venus as it crossed the edge of the sun, and deduced that Venus must possess an atmosphere. Shown here are drawings of Venus and the “black drop effect” by Torben Bergman, later discovered to be caused by image blurring and solar limb darkening.  ”

4. “The transit of Venus on June 3, 1769, led to the publication of 400 sightings.”  This French cartoon depicts the 1769 event.  

5. “Melbourne’s heliograph is the only surviving image from the 1874 transit.”

6. “Composer John Philip Sousa took a great interest in the Venus transit of 1882. During 1882-3, he created the ‘Venus Transit March.’ The Smithsonian Institution commissioned Sousa to compose the piece in honor of American physicist Prof. Joseph Henry, so the march was not specifically produced in commemoration of the transit.”

7. “The December 6, 1882 transit of Venus generated enormous public interest. Smoked glass and amateur telescopes were put into use abundantly. One of the first photographs of the transit of Venus 1882 is shown here.”

Credits: Credit: NASA Goddard Space Flight Center Sun-Earth Day, STFC

(Sources: space.com, Science 2.0) 

Excitement builds for rare transit of Venus on June 5

Scientists are gearing up for the upcoming transit of Venus, an extremely rare opportunity to watch the planet Venus pass in front of the sun as seen from Earth.  Venus is due to make this cosmic crossing June 5-6 — the last time such an event will occur until 2117.



(The 2004 transit of Venus.  Credit: Imelda B. Joson and Edwin L. Aguirre)

“When viewed through special solar filters or protective equipment, the transit should offer skywatchers and amateur astronomers an unforgettable sight, weather permitting. But the event is also a rare opportunity for scientists.”

“As Venus transits the sun, sunlight will be filtered through the planet’s atmosphere. By analyzing the absorption features in this light, researchers can learn more about the chemical elements present in the gaseous haze around Venus.  Many of the world’s premier telescopes will be trained on the sight, including NASA’s Hubble Space Telescope and Solar Dynamics Observatory, as well as the European Space Agency’s Venus Express satellite in orbit around Venus.”

“Because of the peculiarities of the orbits of the planets around the sun, Venus transits are visible from Earth in pairs separated by eight years. The upcoming transit is the second in a pair that began with one in 2004, which at the time was the first visible in more than 121 years.  The 2004 transit provided scientists with the first opportunity to view such an event with modern equipment and telescopes.”

(Skywatchers will want to make every effort to SAFELY observe next week’s Venus transit, the last time such an event will occur likely during the lifetime of anyone alive today.  Full details, including maps and times of visibility, are available at transitofvenus.org.  However, DO NOT LOOK DIRECTLY AT THE SUN without a proper filter!  Viewing the Sun directly can cause damage or permanent loss of vision!  Among the safest ways to view the Sun is through a layer of Number 14 welder’s glass, available from specialty welding supply stores — do not use a less dense type of welder’s glass than Number 14.  Alternately, an image of the Sun can be safely viewed with a pinhole viewer out of a shoebox and some aluminum foil.  -JCB)