Stories tagged The Universe

Aug
16
2006

The 12 planets: In this artist's impression the planets are drawn to scale, but without correct relative distances.  Image courtesy the International Astronomical Union/Martin Kornmesser.
The 12 planets: In this artist's impression the planets are drawn to scale, but without correct relative distances. Image courtesy the International Astronomical Union/Martin Kornmesser.

The international panel that was formed to establish a scientific definition of a planet will make a recommendation to the International Astronomical Union (IAU) General Assembly that will increase the number of objects in out solar system that are defined as planets from nine to twelve.

The panel was originally formed to discuss the issue of Pluto’s status as a planet. Not only does the panel recommend retaining Pluto’s planetary status, but also promoting Ceres, Charon and "Xena" to planets. The new definition of a planet is that it has to orbit a star, not be a star itself, not a satellite of another planet, and massive enough that its gravitational forces compress it into a roughly round shape. This opens the door for many more objects in our solar system to be called planets, notably Vesta, Pallas and Hygiea. In fact, there may be more than 53 objects that meet the new criteria to be called a planet, and probably many more yet to be discovered.

The proposal is not final, and will be discussed on August 23 at the International Astronomical Union General Assembly meeting in Prague.

Watch a fly by of the new solar system here.

UPDATE: Turns out they changed the rules, and we now have only eight planets. Pluto doesn't qualify under the new definitions a planet. To be a “planet” it must:

1. Orbit a sun.
2. Have sufficient mass so that it assumes a nearly round shape.
3. And have sufficient mass to have "cleared the neighborhood around its orbit".

Pluto has not cleared the neighborhood of its orbit of Kuiper Belt Objects, so it is no longer considered a planet.

Aug
09
2006

The impact site.: This artist's impression shows the location of the SMART-1 impact on the Moon surface, expected for 3 September 2006 at 05:41 UT, with an uncertainty of plus or minus 7 hours, due to the unknown lunar topography.  The impact site will be on the lunar area
The impact site.: This artist's impression shows the location of the SMART-1 impact on the Moon surface, expected for 3 September 2006 at 05:41 UT, with an uncertainty of plus or minus 7 hours, due to the unknown lunar topography. The impact site will be on the lunar area
The European Space Agency (ESA) is crashing another spacecraft into another object in space, and I just have to say I like their style! After intentionally crashing into a comet last year, the ESA plans to crash its lunar orbiter, SMART 1, into the moon on September 3, 2006. The best part is that they are coordinating the crash so that it will happen on the visual side of the moon so that it can be seen (using telescopes) from Earth. If all goes according to plan, the impact time will be good for big telescopes in Northwest America. But if the spacecraft hits a hill on earlier passes, the viewing location will change.

SMART-1 launched on September 27, 2003, and tested an array of new technologies, including the first use of an ion engine (solar electric propulsion) for interplanetary travels, deep-space communication methods for spacecraft, and techniques to achieve autonomous spacecraft navigation.

The spacecraft was only planned to operate for six months, but its mission was extended, and will now end on September 3 when it meets its demise on the surface of the moon.

Aug
06
2006

Triangulum galaxy (M33)
Triangulum galaxy (M33)Courtesy NASA

Universe may be 15.8 billion years old

The Hubble constant, formulated by Edwin Hubble in 1929, has remained fairly constant since the 1950's. Kris Stanek, associate professor of astronomy at Ohio State, and his coauthors are publishing a paper that may change the accepted value of the Hubble constant and also the accepted size and age of the universe.

They studied two of the brightest stars in M33, which are part of a binary system, meaning that the stars orbit each other. As seen from Earth, one star eclipses the other every five days.

They measured the mass of the stars, which told them how bright those stars would appear if they were nearby. But the stars actually appear dimmer because they are far away. The difference between the intrinsic brightness and the apparent brightness told them how far away the stars were -- in a single calculation.

To their surprise, the distance was 15 percent farther than they expected: about 3 million light-years away, instead of 2.6 million light-years as determined by the Hubble constant.

Astronomers crunch numbers, universe gets bigger

This new method took 10 years to develop. To make such a drastic change to the accepted view of the universe will require additional experimentation.

"Our margin of error is now 6 percent, which is actually pretty good," Stanek said. Next, they may do the same calculation for another star system in M33, to reduce their error further, or they may look at the nearby Andromeda galaxy. The kind of binary systems they are looking for are relatively rare, he said, and getting all the necessary measurements to repeat the calculation would probably take at least another two years.

Soure article: Ohio State University Research Archive

Jul
23
2006

Cosmic Calendar: Cosmic Calendar; All of time compressed to one year. picture from wikimedia
Cosmic Calendar: Cosmic Calendar; All of time compressed to one year. picture from wikimedia

The history of the universe reduced to one year

Astrophysicists have deduced the age of the Universe (dated from the Big Bang) to be 13.7 BILLION YEARS!
If this time line were compressed into one year, each month would be about one a billion years. What follows is a look at when import events occur during this "cosmic Year".

    Jan 1, Big Bang
    May 1, Milky Way Galaxy origen
    Sept 9, solar system origen
    Sept 14, Earth formation
    Oct 9, oldest fossils (algae)
    Nov 15, 1st cells with nuclei
    December: (1st) oxygen in atmosphere (18th) trilobites, plankton (19th) fish, vertebrates (20th) plants on land (21st) insects, land animals (22) amphibians, winged insects (23) trees, reptiles (24) dinosaurs (26) mammals (27) birds (28) flowers, dinosaurs extinct (29) primates, whales (December 31,10:30p.m.) first humans (11p.m.) stone tools (11:46p.m.) domestic use of fire (11:59:20p.m.) agriculture

Ten second countdown till midnight:

    10 astronomy
    9 alphabet
    8 laws
    7 bronze
    6 iron
    5 Buddha
    4 Archimedes, Ptolomy, Christ
    3 zero and decimals, Rome falls, Islam
    2 Maya, Crusades
    1 science experimentation

During the last second

We have planetary exploration, computers and AI, nanotechnology, global culture, and weapons of mass destruction.
Source article: link

May
22
2006

Jupiter is growing spots. The largest planet in our solar system has long been home to the Great Red Spot, but recently a second red spot, not as large and dubbed ‘Red Spot, Jr.’ by astronomers, was seen to form on the face of Jupiter.

Seen with the naked eye on a clear night, Jupiter, the largest planet in our Solar System, looks like a very bright star. But seen through a powerful telescope, the face of Jupiter crawls with ever-changing sworls of color. The biggest of these sworls is the Great Red Spot. It is an enormous storm, a hurricane three times larger than the entire Earth, which has been raging for over 300 years. 2nd Red Spot on Jupiter: Hubble Space Telescope Image courtesy of NASA.
2nd Red Spot on Jupiter: Hubble Space Telescope Image courtesy of NASA.

‘Red Junior’ was first spotted by Christopher Go in February of this year. The new spot formed from the merger of three, smaller white spots sometime in the past year, and then turned red, just like its larger cousin. The picture here is courtesy of the Hubble Space Telescope.

The Great Red Spot has been know almost as long as telescopes have been around. It was first seen by the Italian astronomer Giovanni Cassini sometime around 1665 and has been an object of fascination and study ever since. No one is exactly sure why it has its reddish color, although one theory is that the storm dredges up gas from deep inside Jupiter and brings it to the surface where it reacts with the sunlight and turns red.

Unlike Earth, which is made of rock surrounded by a thin atmosphere, Jupiter is almost entirely made of gasses. This lack of a rocky core means that there is nothing to slow down or stop violent storms once they get started. They just continue to swirl and combine with each other. Everything on the face of Jupiter changes except the Great Red Spot; it is an island of stability in a sea of chaos. The appearance of a second spot has prompted some astronomers to speculate that Jupiter is undergoing a change in climate.

No one is sure what will happen to Red Junior. It is possible that it will die out, or break up into smaller storms, or even merge with the bigger Spot. Astronomers will be keeping a close eye on it to find out what happens next.

Oct
13
2005

Scientists have finally solved the mystery of gamma ray bursts, the most violent explosions in the universe. Lasting a fraction of a second, they release 100,000,000,000,000 (100 trillion) times more energy than the Sun. But since they were first detected in 1970, scientists have wondered what exactly gamma ray bursts are.

Now, thanks to three satellites and four ground-based telescopes, they have figures out that the explosions occur when two neutron stars collide, or when a neutron star is swallowed by a black hole.

A neutron star is an old star that has burned off most of its fuel and collapsed under its own weight. Though they are only about 10 miles across, they weigh 1 1/2 times as much as the Sun. Gravity squeezes the atoms of together until the protons and electrons merge, forming neutrons.

Collisions between neutron stars can also create black holes. This study may give scientists their first chance to learn how black holes are formed.

Aug
12
2005

This morning at 7:43 AM EDT NASA successfully launched the new Mars Reconnaissance Orbiter into space to begin its long journey to the red planet.


Watch the Launch: MRO Takes offCourtesy NASA

This new mission to Mars will put the satellite into a low orbit to examine the planet in the highest detail ever captured. The orbiter will travel for 8 months before it goes into orbit around Mars.

One of the main goals of this mission is to scout out information that will help us in future missions that will actually land on Mars. So once it gets there it will deploy six new instruments to analyze the atmosphere, scour the surface, and even image deep below the surface of the planet.

  • Atmosphere - One of the cameras aboard the orbiter will give us a daily picture of the global weather on Mars.
  • Surface - The orbiter has the best telescoping camera ever sent to another planet. This will allow us to see crisp pictures of features on the surface as small as your dining room table.
  • Subsurface - The Italian Space Agency built a special ground-penetrating radar that will allow scientists to spot underground water and mineral deposits. This might help us know more about Mars's past and even plan future mining missions for elements not found in abundance on Earth.

Learn more about the Mars Reconnaissance Orbiter and other NASA Mars programs

What do you think is the most important reason to travel to Mars? To mine its resources? For human colonization? To find out it there was/is life on Mars? Something else?

Aug
04
2005

Scientists using the Samuel Oschin Telescope at Palomar Observatory have discovered what they call a planet larger than Pluto in the far reaches of our solar system.

The planet, currently called 2003 UB313, is a trans-Neptunian object which means all or most if its orbit is beyond that of Neptune. The planet is a member of the Kuiper belt, which also claims Pluto and its satellite Charon as members.

A name for the new planet has been proposed by the scientists to the International Astronomical Union, but has not yet been approved until the IAU can determine the minimum size requirement for a planet.

Do you think 2003 UB313 is a planet? What would you name the 10th planet?

UPDATE: The "planet" has been named Eris. Turns out they have changed the rules for what defines a planet, and we now have only eight planets. Neither Eris or Pluto qualify under the new definitions a planet. To be a “planet” it must:

1. Orbit a sun.
2. Have sufficient mass so that it assumes a nearly round shape.
3. And have sufficient mass to have "cleared the neighborhood around its orbit".

Pluto has not cleared the neighborhood of its orbit of Kuiper Belt Objects, so it is no longer considered a planet.

Jun
28
2005

Saturn's moon Titan is the only satellite (moon) in our solar system that has a dense atmosphere. Nitrogen is the main component of this atmosphere and methane the second most important. The Cassini spacecraft photographed Titan as it passed by on October 26, 2004. Later analyses of the images revealed a cryovolcano that spews ice instead of lava. This finding is reported by Christopher Sotin and associates at Universite de Nantes and the Universite de Paris-Sud in France and other institutions in Germany, Italy, and the USA (Arizona, California, Colorado, New York, Washington). This giant ice volcano may also release methane into the atmosphere; however, the images show that a widespread methane ocean does not exist. Because Titan's atmosphere is similar to that of Earth, scientists are studying Titan for clues to the origin of life.

Jun
24
2005

NASA's Deep Impact spacecraft is about to crash a probe into a comet 83 million miles from Earth. This will be the first ever super high speed impact between a comet and a man made probe. The collision is scheduled to take place around 1am Central Time,

Play the DEEP IMPACT game

Comet Game Screenshot

A Satellite flies near a meteor in space.  A large impact shooting gas out can be seen on the surface of the meteor.
Courtesy of NASA/JPL/UMD Artwork by Pat Rawlings

July 4 and will be observed by ground and space based observatories as well as the Deep Impact spacecraft and probes themselves.

Given that the comet, named Tempel 1, is traveling at a speed of roughly 6.3 miles per second, and the probe is only 39 inches wide, there is little room for error. Makes me think of word problems for math class. "If a comet is hurtling through space at 23,000 miles per hour 83 million miles from Earth, and you launched a spacecraft to collide with it 173 days prior to the collision, how fast must the spacecraft travel to deploy a probe to impact the comet on July 4?"

Learn more about this amazing mission by visiting the Deep Impact website.