Watch the Two Brightest Planets Kiss in Twilight

By: The Editors of Sky & Telescope August 19, 2005 0

August 19, 2005

Contacts:
Alan MacRobert, Senior Editor
855-638-5388 x151, [email protected]
Marcy McCreary, VP Mktg. & Business Dev.
855-638-5388 x143, [email protected]

Note to Editors/Producers: This release is accompanied by publication-quality illustrations and a broadcast-quality animation; see details below.

Anyone who looks low in the west early on a clear evening for the next couple weeks will witness an unusual sight. Venus and Jupiter, the two brightest planets, will draw closer and closer together from day to day, will then have an eye-catching conjunction (close pairing) on the evenings of August 31 to September 2, 2005, and then will begin to move apart.

The direction to look is low in the west-southwest, and the best time is about 40 to 60 minutes after your local sunset. The brightest of the two "stars" shining there will be Venus. Jupiter closes in on it from the upper left during August and passes closest to it on September 1st, when the two will appear separated by hardly the width of your finger held at arm's length (about 1.2 degrees).

Also in the vicinity is the much dimmer star Spica. If Spica isn't bright enough to show through the twilight, binoculars should reveal it easily. In addition, the waxing crescent Moon joins the party on September 6th and 7th.

Accompanying this release is a series of daily sky scenes that illustrate what to look for in the fading twilight on any date from August 21st through September 7th. They can also be played in sequence as a QuickTime movie to show the dance of the planets, Spica, and the Moon throughout this period.

Although these objects appear the same distance away as you watch them in the deepening dusk, this is very much an illusion. Venus is roughly 106 million miles from Earth (its distance changes during the period illustrated), while Jupiter is 575 million miles away, more than five times farther. The Moon is about 220,000 miles distant; Spica lies 1.5 quadrillion miles in the background.

Such big distances are better expressed by how long it takes light to cross them. Venus is about 10 light-minutes from Earth. Jupiter is 52 light-minutes from us, the Moon is only 1.2 light-seconds away, and Spica is some 260 light-years away. The light reaching your eyes from these sights has been in flight for very different amounts of time — something to think about when gazing at this unearthly view.

Sky & Telescope is pleased to make several publication-quality illustrations and a broadcast-quality animation available to the news media. Permission is granted for one-time, nonexclusive use in print and broadcast media, as long as appropriate credits (as noted in the caption) are included. Web publication must include a link to SkyandTelescope.com.

The bright planets Venus and Jupiter form a spectacular pair in late August and early September 2005. They're closest on September 1st, when Jupiter shines only about 1.2° to the upper right of Venus. Click on the image to download (by anonymous FTP) a QuickTime animation (553-kilobyte MOV file) showing the changing scene each evening from August 21st through September 7th.

Sky & Telescope illustration and animation by Gregg Dinderman.

Use these text links to download (by anonymous FTP) publication-quality versions (2.9-megabyte TIF files) of the animation's individual frames: Aug. 21, Aug. 22, Aug. 23, Aug. 24, Aug. 25, Aug. 26, Aug. 27, Aug. 28, Aug. 29, Aug. 30, Aug. 31, Sept. 1, Sept. 2, Sept. 3, Sept. 4, Sept. 5, Sept. 6, Sept. 7.

Sky Publishing Corp. was founded in 1941 by Charles A. Federer Jr. and Helen Spence Federer, the original editors of Sky & Telescope magazine. The company's headquarters are in Cambridge, Massachusetts, near the Harvard-Smithsonian Center for Astrophysics. In addition to Sky & Telescope and SkyandTelescope.com, the company publishes Night Sky magazine (a bimonthly for beginners with a Web site at NightSkyMag.com), two annuals (Beautiful Universe and SkyWatch), as well as books, star atlases, posters, prints, globes, and other fine astronomy products.