Vesta & Uranus

Palomar · 2004-10-06 14:02:19

http://skyandtelescope.com/observing/ob … _1.asp]Two gems in Aquarius

*They'll be flirting with either just visible with the unaided eye or requiring binoculars/telescope. Short article includes map. Can view both beginning this month and through to December. :up:

--Cindy

::edit:: "Interestingly, both Vesta and Uranus could have joined the list of naked-eye planets in ancient times — had anyone mapped the sky carefully. Vesta reaches magnitude 5.4 at some oppositions, and Uranus is never fainter than 6.0."

SpaceNut · 2004-10-13 13:21:22

Vesta is a very interesting asteriod in its own little odd shape about the size of arizona. The Hubble has been used to image it as well as the keck and other observatories. Supposedly fragments from it where found in the early 70's after being seen in 1960 by two fence workers in Millbillillie, Western Australia. The fragments stood out from the area's reddish sandy soil because they had a shiny black fusion crust when it was finally located 10 years later.

Nasa had in 2001 a discovery mission called Dawn that was slated for launch in 2006, which would have orbited the two largest asteroids in our solar system.

I am not in the know as to if this mission has been cancelled or not, Anyone in the know?

http://www-ssc.igpp.ucla.edu/dawn/

Palomar · 2004-10-13 14:23:23

Nasa had in 2001 a discovery mission called Dawn that was slated for launch in 2006, which would have orbited the two largest asteroids in our solar system.
I am not in the know as to if this mission has been cancelled or not, Anyone in the know?

http://dawn.jpl.nasa.gov/]Ask and ye shall receive

*Yep, still on. Here's the homepage ala good ol' JPL. Have always wanted to visit JPL since childhood.

--Cindy

Palomar · 2004-11-09 07:09:46

*Here's some further interesting info about Vesta. Universetoday.com hosts a weekly "rundown" of current goings-on in the sky:

Asteroid Vesta is considered to be a minor planet since its approximate diameter is 525 km (326 miles) wide, making it slightly smaller in size than the state of Arizona. Vesta was discovered on March 29, 1807 by Heinrich Olbers and it was the fourth such "minor planet" to be identified. Olbers discovery was fairly easy because *---->Vesta is the only asteroid bright enough at times to be seen unaided from Earth.<----* Why? Orbiting the Sun every 3.6 years and rotating on its axis in 5.24 hours, Vesta has an albedo (or surface reflectivity) of 42%. Although it is about 220 million miles away, pumpkin-shaped Vesta is the brightest asteroid in our solar system because it has a unique geological surface. Spectroscopic studies show it to be basaltic, which means lava once flowed on the surface. (Very interesting since most asteroids were once though to be rocky fragments left-over from our forming solar system!)
Studies by the Hubble telescope confirmed this, as well as a large meteoric impact crater which exposed Vesta's olivine mantle. Debris from Vesta's collision then set sail away from the parent asteroid. Some of them remained within the asteroid belt near Vesta to become asteroids themselves with the same spectral pyroxene signature, but some escaped through the "Kirkwood Gap" created by Jupiter's gravitational pull and allowed these small fragments to be put into an orbit that would eventually bring them "down to Earth". Did one make it? Of course! In 1960 a piece of Vesta fell to Earth and was recovered in Austrailia. Thanks to Vesta's unique properties, the meteorite was definitely classified as once being a part of our third largest asteroid.

--Cindy

SpaceNut · 2004-11-10 14:36:44

The Keck Telescope in Hawaii has provided insight into some of the most enigmatic weather in the solar system.
New Images Reveal Clouds on Planet Uranus

Palomar · 2004-11-10 15:12:24

The Keck Telescope in Hawaii has provided insight into some of the most enigmatic weather in the solar system.
http://space.com/scienceastronomy/uranu … 0.html]New Images Reveal Clouds on Planet Uranus

*I just read the Yahoo! article pertaining to this. Fascinating all around, and am especially enjoying the comparisons with Neptune. :up:

"The cloud features range from small to large, from dim and diffuse to sharp and bright, from rapidly evolving systems to stable features that last for years,"
A large storm in the southern hemisphere seesaws over 5 degrees of latitude during several years.
"It's weird behavior that hasn't been recognized before on Uranus," Sromovsky said. "It's similar to what's been seen on Neptune, although there the oscillation is much more rapid.
Sromovsky added that it's not surprising to see cloud features drifting in latitude, but models don't predict the movement. "We don't know what makes it keep coming back to its starting point," he said.
The pictures also reveal a long, narrow complex of cloud features that is probably the largest group of atmospheric features ever seen on the planet. Spotted in the northern hemisphere, the 18,000-mile-long complex of clouds dissipated completely over the span of a month.
"These more dynamic systems seem to develop at northern latitudes where they rise to even higher latitudes, apparently using up energy and dissipating relatively rapidly," Sromovsky said.
The cloud features are being used to trace and help define wind patterns and predict the motions of the large storm systems that sweep across the pale blue planet.
"The large, longer-lived cloud features of Uranus may be underpinned by giant hurricane-like vortices, as we've seen on Neptune," says

--Cindy

::EDIT:: The relationship of Uranus' orientation (yep -- on its side) to its weather? ???

A bizarre feature is how far over Uranus is tipped. Its north pole -- representing the planet's axis of rotation -- lies 98 degrees from being directly up and down to its orbit plane, which means the planet is essentially on its side in relation to the Sun. Thus, its seasons are extreme: when the Sun rises at its north pole, it stays up for 42 Earth years; then it sets and the north pole is in darkness for 42 Earth years.

Palomar · 2004-11-10 18:39:35

*Ah...another http://www.spaceref.com/news/viewpr.htm … ]excellent article about Ouranos with info not disclosed in SpaceNut's 1st article, nor the Yahoo! article I copied and pasted later.

Lovely photo too.

Definitely like the name "Ouranos" much better. :up:

used advances in Keck adaptive optics (AO) to help make major scientific discoveries regarding the planet's atmosphere and ring system...
On Earth, the massive storms captured in the new pictures of Uranus would engulf nations as large as the continental United States, about 3 million square miles...
the ring system is more readily visible through the 2.2-micron filter because methane absorption at this wavelength renders the planet extremely dark except for a few high altitude clouds. In contrast, the 1.6-micron image shows deeper atmospheric cloud structure, including many discrete features peppering the planet's northern hemisphere. At 1.6 microns, the rings are just barely visible as a faint streak across the planet's northern hemisphere.

*Really gets my curiosity going bonkers:

In 1986, the Voyager 2 spacecraft sent pictures to earth of what appeared to be a non-descript ball suspended in space. At that time, Uranus' South Pole was pointed almost directly at the sun, and the North Pole pointed away. Now, more than 18 years later, the planet is drawing near the point in its orbit where the planet's equator will be pointing toward the Sun, and both poles will get about 17 hours of sunlight a day.

*How DOES that drive the weather? Phenomenal!

--Cindy

P.S.: Let's please continue the discussions about today's new Uranus discoveries in http://www.newmars.com/forums/viewtopic.php?t=2923]New Discoveries *4*, which is more suited for it. The original purpose of this thread (Vesta & Uranus) concerned the "placement" of both celestial bodies in Aquarius, possible unaided eye/telescopic viewing of both, etc. Thanks.

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#1 2004-10-06 14:02:19

Re: Vesta & Uranus

#2 2004-10-13 13:21:22

Re: Vesta & Uranus

#3 2004-10-13 14:23:23

Re: Vesta & Uranus

#4 2004-11-09 07:09:46

Re: Vesta & Uranus

#5 2004-11-10 14:36:44

Re: Vesta & Uranus

#6 2004-11-10 15:12:24

Re: Vesta & Uranus

#7 2004-11-10 18:39:35

Re: Vesta & Uranus

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