Geology News - Earth Science Current Events

Image by NASA

NASA scientists have found a giant storm on Saturn that appears to operate like a hurricane. This storm is about 8000 km / 5000 miles across and is located right above Saturn's south pole. It appears to rotate in a clockwise direction with a speed of about 550 kilometers per hour / 350 miles per hour.

This storm was discovered using telescopic cameras on NASA's Cassini spacecraft and is the first hurricane-like storm to be observed on a planet other then Earth. The storm appears to have eyewall clouds and two spiral arms, similar to hurricanes that we know on Earth. (Jupiter's Great Red Spot does not have an eyewall and is calm at the center).

Read more about this hurricane-like storm on Saturn and watch a short movie of the storm's motion at the Cassini-Huygens Mission to Saturn website.

Labels: Astronomy-Planets

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Image by USGS

Last summer the International Astronomical Union demoted Pluto from the status of "planet" to that of "dwarf planet." This was done because Pluto did not fit the new definition of a planet, which included a requirement for it to have cleared the neighborhood around its orbit. The vote to demote Pluto was not unanimous and now several prominent scientists are calling for a new definition of what it takes to be a planet - one that they hope will reinstate Pluto.

A Newsweek article at MSNBC details how Bob Millis, Director of the Lowell Observatory; Mark Sykes, director of the Planetary Science Institute in Tucson; and Alan Stern, principal investigator of the New Horizons space-probe mission, scheduled to arrive at Pluto in 2015, are all hoping to restore Pluto's status. It might be premature to burn your solar system astronomy textbooks - a movement to create a new definition of the term "planet" might gain momentum before the IAU meets in 2009.

Read the article, Plotting Pluto's Comeback for full details.

Related Article on Geology.com - Pluto is Now a Dwarf Planet

Labels: Astronomy-Planets

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About 500 million years ago two spiral galaxies began colliding with one another. The collision is still in progress and was captured by the Hubble Telescope. Known as the Antennae Galaxies, this area of space is now the birthplace of billions of new stars.


Antenna Galaxies - Image by NASA
NASA's interpretation of this image...

Nearly half of the faint objects in the Antennae image are young clusters containing tens of thousands of stars. The orange blobs to the left and right of image center are the two cores of the original galaxies and consist mainly of old stars criss-crossed by filaments of dust, which appears brown in the image. The two galaxies are dotted with brilliant blue star-forming regions surrounded by glowing hydrogen gas, appearing in the image in pink.

This image is helping astronomers learn more about how stars form in a galactic collision and will help them predict what will happen when our own Milky Way Galaxy collides with the Andromeda Galaxy a few million years from now.

Get a much closer look using a zoomable image of the Antenna Galaxies at the NASA website.

Labels: Astronomy-Planets

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The Mars Reconnaissance Orbiter is sending lots of fantastic images back to Earth. These are some of the highest quality images of the planet, both in terms of scenic views and in processed images that take advantage of the spectral data.

The image below is of the Northern Mars polar area near the middle of the planet's summer. The Mars Reconnaissance Orbiter is focusing on this area now because the continued southern movement of the sun will reduce polar illumination. The next opportunity to get well illuminated images of northern areas will not be until 2008.


Image by NASA
The image set below consists of a true color and false color infrared views. However, more interesting are the images showing iron-rich clays and aluminum-rich clays. These images were prepared by showing the brightness of selected infrared wavelengths that are characteristic of specific minerals. The resulting image is a "map" of the distribution of those minerals.


Image by NASA

View more Mars Reconnaissance Orbiter images at the MRO Website.

Labels: Astronomy-Planets, Satellite-Images

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Image by NASA Mars Global Surveyor

The Mars Reconnaissance Orbiter was launched in August 2005 and placed itself into a Mars orbit position in March 2006. It is now braking and descending into operating position and is already returning a variety of data.

One of the main jobs of the Orbiter is to gather information about the geology of Mars. Shallow radar will look beneath the surface for the presence of liquid or frozen water, images will be returned to look for features such as ancient lakebeds, salt flats, and mineral deposits.

In the image at right (taken by Mars Global Surveyor) gullies originate at the base of a specific rock layer. These gullies may have formed when these rock layers released groundwater to the Martian surface in geologically recent times. The Mars Reconnaissance Orbiter will take much higher resolution images. These images will be used to identify which areas of the planet's surface might be good candidates for scientific study and which might be hazardous to future missions which could carry humans.

Spectrometers on the Orbiter will scan the Martian surface, splitting visible and near-infrared light into hundreds of "colors" that identify minerals. This data can then be used to map the distribution of minerals.

Learn more about these geological studies and more at the Mars Reconnaissance Orbiter Homepage.

Labels: Astronomy-Planets, Minerals

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Image by NASA

Mars Exploration Rover Opportunity has reached the edge of Victoria Crater, a 730-meter wide impact crater. This destination should be one of the most interesting and valuable stops by Opportunity. The navigation camera on the top of Opportunity's mast has taken many images, some of which were used to create the composite panorama below showing the rocky walls of Victoria Crater.

Image by NASA
Because craters are holes in the surface of Mars, scientists now have an opportunity to examine layers of material below the Martian surface which could reveal new information about the history of Mars. Opportunity has visited other craters, however, Victoria Crater is the deepest - a depth of about 70 meters. This gives an opportunity to examine additional subsurface materials which are probably much older than those observed in previous craters.


Image by NASA
The image above is an aerial view of Victoria Crater. The bottom of the crater is covered by sand that has been shaped into ripples by the Martian wind.

Learn more and see thousands of images at the Mars Rover Website.

Labels: Astronomy-Planets

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Image of Pluto and Charon by NASA

The International Astronomical Union has defined a "planet" as a celestial body that: 1) orbits the Sun, 2) is of sufficient mass for its self-gravity to overcome rigid body forces and assume a nearly round shape, and 3) has cleared the neighborhood around its orbit.

Under this definition, Pluto is demoted from a "planet" to a "dwarf planet" and our Solar System is left with eight "planets": Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. A new class of objects called "dwarf planets" was created. Ceres, Pluto and 2003 UB313 are the first dwarf planets and more are expected to be announced in the future as studies and discoveries occur.

A "dwarf planet" is defined as a celestial body that 1) orbits the Sun, 2) is of sufficient mass for its self-gravity to overcome rigid body forces and assume a nearly round shape, 3) has not cleared the neighborhood around its orbit, and 4) is not a satellite.

Textbooks, posters, mobiles and the memory of most people over 6 years of age will now need modification.

Labels: Astronomy-Planets

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Solor System Art by NASA

Why can't astronomers agree on the status of objects in our Solar System? The short answer is that their knowledge of the Solar System is constantly improving. About 200 years ago our Solar System consisted of a central sun, planets that orbited the Sun, and moons that orbited the planets. The Solar System was very simple.

However, powerful telescopes, other measurement instruments and space craft capable of capturing detailed images and data have all been used to learn many new things about the objects in our Solar System. We now know about large numbers of asteroids orbiting the Sun between Jupiter and Mars and the Kuiper Belt Objects that orbit the Sun in the distant parts of our Solar System.

Should these small objects be called planets or should the word "planet" be reserved for objects of significant size and spherical shape? That's where the definition of a "planet" becomes problematical. How small can a planet be? How round must it be?

Until this month the objects that we call "planets" have been based upon historic designations that were made before large numbers of asteroids and Kuiper Belt Objects were discovered that competed with the traditional planets for attention. So, now astronomers are finally forced to come up with a very specific definition of what is a planet and what is not.

According to the draft definition of International Astronomical Union a planet must... 1) orbit a star, and 2) be massive enough for its own gravity to form itself into a spherical shape.

If the IAU approves this definition then there will be 12 planets in our Solar System - the current nine planets plus: Ceres (an asteroid - initially called a planet when it was discovered in 1801 but was stripped of planetary status about fifty years later when its true size was calculated and it was considered too small for a planet), Charon (a companion of Pluto in the Kuiper Belt), and 2003 UB313 (another Kuiper Belt Object discovered in 2003 - many astronomers wanted it to be named as the 10th planet and that debate is probably what forced the current need for a "planet" definition).

The IAU will vote on the draft definition of a planet on August 24. If this definition is approved it opens the way for additional planets to be proposed as the Kuiper Belt Objects are studied in greater detail - and who knows what discoveries will be found in the future.

Labels: Astronomy-Planets

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Image by NASA showing the relative size of Pluto and its moon Charon, compared to the United States

Pluto has been considered the ninth planet since its discovery in 1930. It has three moons (Charon, Nix and Hydra) and orbits the sun much like the rest of the undisputed planets.

However, the International Astronomical Union, meeting in Prague this week, might decide to remove Pluto from the list of planets.

NASA Image of Pluto and Moons.

This debate started back in the 1990's as astronomers realized that Pluto was just one of many objects with similar behavior that travel around the Sun in the Kuiper Belt.

The discovery of Xena in 2003, another Kuiper Belt object - larger than Pluto and farther from the Sun - intensified the debate about Pluto's status as a planet. Some astronomers expressed concern that there was no precise definition of a "planet" and that large numbers of Kuiper Belt objects could be proposed for planetary status.

Read more about the debate to keep or demote Pluto from planet to a pedestrian Kuiper Belt object.

Labels: Astronomy-Planets

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The Hubble Space Telescope has captured views showing the break-up of Comet 73P/Schwassmann-Wachmann 3. The comet is breaking up in response to the thermal, gravitational and dynamical stresses of approaching the sun.


Image by NASA

Read and see more images of the Comet Break-up at the Hubble Website.

Labels: Astronomy-Planets

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A total solar eclipse passed over northern Africa and the Mediterranean on Wednesday, March 29. The event is captured on the satellite image sequence shown below. In this solar eclipse sequence you can see a black area (shadow of the Moon) move from the bottom center of the image to the top right corner of the image. The dark black area, about 160 kilometers (100 miles across) is the region of "totality" where the moon is completely eclipsing the sun.)


Image modified from a NASA animation.

Labels: Astronomy-Planets

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Astronomers Peter Eisenhardt and Mark Brodwin of NASA's Jet Propulstion Laboratory have discovered the farthest away object ever seen using NASA's Spitzer Space Telescope. They measured the color of distant galaxy clusters and used that information to estimate their distance from Earth.

Galaxy clusters are the largest gravitationally bound structures in the universe. A typical cluster can contain thousands of galaxies and trillions of stars.

Their methods detected a galaxy cluster that is over 9 billion light years from earth. This means that the light detected by the Spitzer telescope left that galaxy cluster over 9 billion years ago - about 4.5 billion years before the earth was formed! Looking into deep space with the Spitzer telescope is really looking back in time.


Image by NASA/JPL

In the false-color composite image above the red dots are distant galaxies, the green blobs are Milky Way stars and the blue specks are faint galaxies at various distances along the line of sight. The cluster at 9.1 billion light-years away (lower right panel) is currently the most distant galaxy cluster ever detected.

Read more about looking back in time at the Spitzer Space Telescope Website.

Labels: Astronomy-Planets

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Google now has a shaded relief map of Mars that you can use explore the planet's surface. Tools allow you to zoom and pan, and pushpins are used to mark over 100 features. A person interested in geomorphology or planets could spend an awful lot of time exploring the mountains, plains, craters and canyons of Mars.

screenshot of Google Mars websiteCheck out the Shaded Relief Map of Mars by Google.

Labels: Astronomy-Planets

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A big surprise has surfaced from the Cassini-Huygens Mission - the discovery of what is thought to be water on Saturn's moon Enceladus. "We realize that this is a radical conclusion -- that we may have evidence for liquid water within a body so small and so cold," said Dr. Carolyn Porco, Cassini imaging team leader at Space Science Institute, Boulder, Colorado. "However, if we are right, we have significantly broadened the diversity of solar system environments where we might possibly have conditions suitable for living organisms."

The Cassini images below show what are thought to be icy jets and plumes of water ejected at high speed. NASA scientists believe that these jets might be erupting from near-surface reservoirs of liquid water - at temperatures above zero degrees Celsius. They have been compared to geysers similar to Old Faithful in Yellowstone.

Image by NASA

Read more about water on Saturn's Moon Enceladus at the NASA website.

Labels: Astronomy-Planets

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Many new images of Saturn and its moons are being shared with the public at the Ciclops.org website. There is a lot of geology to be seen in these images with just a small sampling below.

Hyperion has a spongy-looking surface that is thought to result from thermal erosion, a process through which dark materials accumulating on crater floors are warmed by sunlight and melt deeper into the surface.


Image by NASA (more detailed image)

Rhea is heavily cratered, has faults in many orientations and shows evidence of volcanism.


Image by NASA (more detailed image)

Dione is also heavily cratered. JPL scientists speculate that the whispy appearance is caused by material of high albedo that is thin enough to allow surface features to be unobscured. This material might have been ejected from fractures in Dione's surface and fell back to the surface as snow or ash.


Image by NASA

Learn more about the moons of Saturn at Ciclops.org and Planetary Photojournal.

Labels: Astronomy-Planets

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The image below is a tiny view of the most detailed image of a spiral galaxy that has been assembled to date. It is a mosaic created by NASA / STScI using 51 individual exposures from the Hubble Space Telescope plus elements from ground-based photos.

Shown in the image is M101, also known as the Pinwheel Galaxy, which is located in the Ursa Major constellation. It is 25 million light years from earth. It is a giant spiral disk of stars, dust and gas and is 170,000 light years across - nearly twice the diameter of the Milky Way Galaxy.

Image by NASA / STScI (more detailed image)Read more about the Spiral Galaxy Image at HubbleSite.org.

Labels: Astronomy-Planets

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NASA reports a new red spot on Jupiter. The new red spot, named "Oval BA," but most refer to it as "Red Jr." is about 1/2 the size of the famous "Great Red Spot". The large red spot and this new one are thought to be caused by long-term storm systems and the Great Red Spot is the largest known storm in the solar system.

Oval BA was first noticed in 2000 when three small storms, which were white in color, collided and merged. The combined spot was initially white then brown and a few weeks ago turned red.

Read more about Jupiter's New Red Spot at the NASA website.

Labels: Astronomy-Planets

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NASA scientists are "ecstatic" about the dust recovered from the comet Wild 2. This is the second time in history that a vehicle from Earth has brought back natural materials from space - the first being the 1972 Apollo mission.

These "comet dust" particles were captured in January 2004 as the Stardust spacecraft flew within 149 miles of comet Wild 2 on its seven-year mission. Some of the particles are large enough to be seen with an unaided eye. They will be analyzed and distributed to a worldwide team of scientists.

Image by NASARead more about the dust from comet Wild 2 at the NASA website.

Labels: Astronomy-Planets

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Earth and Sky has posted an interview with Paul Spudis, a planetary scientist at the Johns Hopkins University Applied Physics Laboratory in Baltimore, Maryland. His specialty is the geology of the Moon. He has also studied the geology of Mars, Mercury, and many other worlds. Dr. Spudis was Deputy Leader of the science team for the Clementine lunar mission in 1994, and has participated in NASA and National Academy of Sciences committees that helped shape future space exploration.

The interview begins with how he became interested in planetary science and includes details on how the concept of lunar ice produced a turn-around in his thinking. Stories on how great scientists have the courage and wisdom to change their minds are always interesting.

Read more at Earth and Sky.

Labels: Astronomy-Planets

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Google maps has posted images of the lunar landing sites - Apollo 11, Apollo 12, Apollo 14, Apollo 15, Apollo 16 and Apollo 17. You can zoom and pan over a limited portion of the moon surrounding these sites and get interesting views of craters and other features. You can also click on the landing sites to see information about the mission and the astronauts.

Image by NASACheck it out at Google's Apollo Landing Sites

Labels: Astronomy-Planets

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