Cap'n Bob & the Damsel

Astronomy

Mercury to Transit the Sun Today

UPDATE 2: A Segment of a heliograph taken in Hawaii shows a tiny dot near the center. The dark spot on the left is a sunspot that is rotating towards Earth.

UPDATE: Astronomy Picture of the Day shows just how unspectacular the transit will appear.

Don’t get your hopes up for a spectacular view of this event. Even with eclipse glasses, mercury’s image will appear to be so very tiny compared to the solar disk.

Left: A prior Mercury transit as observed by SOHO

If you have a pair of binoculars available, you might try and project the sun’s image onto a flat, shaded surface. Point the objective lens (the end you don’t look through) toward the sun and try to focus the solar disk onto the flat surface. DO NOT LOOK AT THE SUN THROUGH THE BINOCULARS!

If you plan to try and observe the event, for God’s sake, do not look at the sun without the proper solar filters — instant damage can be done to your eyes.

From NASA:

NASA – 2006 Transit of Mercury

On Wednesday, Nov 8th, the planet Mercury will pass directly in front the Sun. The transit begins at 2:12 pm EST (11:12 am PST) and lasts for almost five hours. Good views can be had from the Americas, Hawaii, Australia and all along the Pacific Rim.

[Read more]

08 Nov 2006 by Astronomy Rocket Science

Samhain

Today is the autumnal cross-quarter day. Like equinox and solstice, a cross-quarter day identifies a place in the Earth’s orbit. Cross-quarters occur at the midpoint between solstice and equinox.

Image: Diagram of solstices, equinoxes and cross-quarter events. (Courtesy Archaeoastronomy.com — Click for an animated version)

Ancient Celtics celebrated cross-quarter days as significant events in their calendar. Samhain marked the end of the harvest and the end of summer. Samhain is the word for November in the Irish language. The same word was used for a month in the Celtic calendar, in particular the first three nights of this month, with the festival marking the end of the summer season and the end of the harvest. A modernized version of this festival continues today in some of the traditions of the Catholic All Saints’ Day, the secular Halloween, and in folk practices of Samhain itself in the Celtic Nations and the Irish and Scottish diasporas.

Archeoastronomy.com is an interesting site to visit. Go there and read about the ancient peoples celebration of celestial events. Also visit Old News and read about the possibility that ancient Native Americans may have been influenced by the Celtic calendar! Fascinating stuff.

07 Nov 2006 by Astronomy Culture

Death of a Comet


Did you ever see a comet plunge into the sun? Not likely unless you have seen images from the Solar and Heliospheric Observatory (SOHO). Watch as the comet strikes the heliosphere and causes a solar explosion.

Image: Courtesy NASA and SOHO

Spaceweather.com says:

Yesterday, the Solar and Heliospheric Observatory (SOHO) caught a comet plunging toward the sun. It went in–but not out again. The sungrazing comet disintegrated like an ice cube in an oven.

In the animation, the white circle represents the outline of the sun. The dark circle is a shield in the optics to block the solar image so background activity and objects may be seen. Above and to the left is the planet Venus which just passed above and in front of the Sun. In a wider field of view image, the planet Mars can also be seen along with labels explaining the image.

05 Nov 2006 by Aerospace Astronomy Rocket Science

The Rings of Saturn

This photo, taken by the Cassini-Huygens Probe shows Saturn’s rings as we’ve never seen them. Taken from behind the planet while the Sun was eclipsed, the photo reveals that there are more rings than previously believed.

Funny things happen when you get the illumination coming from behind an object. Damsel once took a photo of Air Force One that gave the illusion of a transparent vertical stabilizer.

Read the whole story: NASA Finds Saturn’s Moons May be Creating New Rings

17 Oct 2006 by Aerospace Astronomy Rocket Science

Convergence

Over the next several days, Mars and Venus will converge on the Sun. This graphic (courtesy SOHO and NASA) is a movie of solar coronagraph pictures taken over the last few days. The outline of the Sun is the small white circle in the center. The dark circle is the solar shield in the imaging instrument. This allows images of the solar corona to be collected in spite of the bright light.

While not designed for this purpose, stars and planets are also frequently imaged. In the coming weeks planets Mars and Venus will pass behind and in front of the Sun, respectively. Neither planet will transit, or pass directly through the solar disk, but slightly above the ecliptic plane (defined by the orbit of the Earth).

Transits of Venus across the disk of the Sun are among the rarest of planetary alignments. Indeed, only seven such events have occurred since the invention of the telescope (1631, 1639, 1761, 1769, 1874, 1882 and June 8, 2004). Venus will do an encore on June 6, 2012. After that, it will pass above or below the solar disk for another 105 years or so.

05 Oct 2006 by Aerospace Astronomy Science

Hubble Back in Action

Slowly, this amazing instrument is becoming out-of-date, and things seem to be wearing out on it. Yet, because of backup systems, on-site repairs and remote engineering excellence, it keeps on ticking. Hopefully, it will remain functional until the James Webb Space Telescope becomes operational.

From NASA:

Hubble’s Advanced Camera for Surveys Resumes Exploring the Universe

After a brief hiatus, the Advanced Camera for Surveys aboard NASA’s Hubble Space Telescope is back in business, probing the far reaches of space in a quest to understand the true nature of the universe’s most dominant constituent: dark energy.

This is one of the first images of the universe taken after the ACS camera resumed science operation on July 4. The camera was offline for nearly two weeks as NASA engineers switched to a backup power supply after the camera’s primary power supply failed.


Image above: A cluster of galaxies with recent supernova. Image Credit: NASA.

02 Oct 2006 by Astronomy Science

Man-Made Sunspots

I’ve written about solar phenomena and sunspots several times in our Global Warming category, but haven’t covered the man-made variety. This is from APOD:

Sharp Silhouette

Though it’s 93 million miles away, the Sun still hurts your eyes when you look at it. But bright sunlight (along with accurate planning and proper equipment!) resulted in this sharp silhouette of spaceship and space station. The amazing telescopic view, recorded on September 17, captures shuttle orbiter Atlantis and the International Space Station in orbit over planet Earth. At a range of 550 kilometers from the observing site near Mamers, Normandy, France, Atlantis (left) has just undocked and moved about 200 meters away from the space station.

Image and story excerpt courtesy APOD and NASA.

21 Sep 2006 by Aerospace Astronomy Photography

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