Skip to main content

Mercury Revealed: Smallest Planet Is Further Shrinking

By Alice Turner
23:00, July 4th 2008

NASA revealed images sent by its MESSENGER probe in January, when it snapped up some 1,200 photos taken from some 120 miles from the planet's surface. MESSENGER, the MErcury Surface, Space ENvironment, GEochemistry and Ranging spacecraft launched by NASA in 2004, raced past Mercury on January 14 in the first visit in almost 33 years to the mysterious small planet, in the first of four sweeps over Mercury by the probe.

Now, scientists have analyzed these unprecedented images and have come up with 11 papers published yesterday, July 3, in Science. It appears that the innermost planet of our solar system has shrunk by more than a mile in diameter over its history. It appears that the planet's metal core is still active, but its cooling causes the upper-most layers to solidify and sink into the molten layers below.

The analysis also indicates an abundance of silicon, sodium and sulfur in Mercury's core. Mercury, named after the Roman god Mercurius, is orbiting the Sun once every 88 days, with a volume of 0.054 Earths and a surface of 0.108 Earths.

Launched on a Boeing Delta II rocket, MESSENGER lifted off from Cape Canaveral Air Force Station, Florida at 02:15:56 EDT on August 3, 2004 with the goals to determine the chemical composition of Mercury's surface, its geologic history, the nature of the planet's magnetic field, the size and state of the core, the volatile inventory at the poles, and the nature of Mercury's exosphere and magnetosphere.

However, MESSENGER's most important mission is yet to come: its Mercury orbit insertion will be on March 18, 2011, beginning a year-long orbital mission which will see a lot more data sent to Earth.

The space probe is also interesting because its navigation team is lead by KinetX, the first private company to be responsible for navigation of a NASA deep space mission. Their experts are fully responsible for determining all trajectory adjustments throughout the probe's flight through the inner solar system ensuring that MESSENGER arrives at Mercury with the proper velocity for orbit insertion.

The robotic space probe Mariner 10 was the only spacecraft so far to approach Mercury, and managed to map about 40 percent of its surface. Its mission ran between 1974 and 1975 and the probe was the first spacecraft to make use of an interplanetary "gravitational slingshot" maneuver.

Comments

Post a Comment

Popular posts from this blog

The Olympic Diet of Michael Phelps!

By Kathleen M. Zelman, MPH, RD, LD WebMD Health News Questions and answers about the high-calorie diet that fuels the Olympic swimmer's championship performance. Aug. 13, 2008 -- His body may resemble the trim, athletic figure of Michelangelo's statue of David, but the diet of Michael Phelps sure doesn't sound like the stuff of champions. The U.S. Olympic swimmer told ESPN that he eats roughly 8,000-10,000 calories a day, including "lots of pizza and pasta." In addition to stuffing down carbs, he's said that he routinely eats foods like fried egg sandwiches. So exactly how do all those calories help fuel the most decorated Olympic athlete in history? Here are some questions and answers about the Michael Phelps diet. How can Michael Phelps eat 10,000 calories a day and still be so lean? There is no doubt he packs away a ton of food, but it is unlikely that he actually eats that many calories a day, an expert believes. University of Pittsburgh Director of Sports...
Post a Comment
Read more

How to Stay Fit and Healthy

You did it! You met your fitness goal! Now that you have achieved some of your health-related goals, you'll need to focus on  staying  in shape and maintaining a healthy diet. You may have changed a lot of things about what you eat, your lifestyle, and/or your exercise routine. Sometimes keeping up with all the great changes you've made to be more fit or healthy can be daunting. Many people have difficulty maintaining these changes long-term. It can make you feel overwhelmed or get tired or bored with the lifestyle you've developed. But there are a lot of ways that you can stay motivated and keep up with your healthy lifestyle. 1 Touch base your doctor and registered dietitian.  When you are changing your focus from losing weight or meeting a certain goal to maintaining the healthy body you have fought hard to achieve, your dietary needs may change, too. Before becoming fit and healthy you likely met with your doctor and/or a dietitian, and now would be a good t...
Post a Comment
Read more

How to Tell if Someone Is Being Sarcastic

1. Most of the time, people will change the tone of their voice when they are being sarcastic. 2. Listen for a flat, uncaring tone, or an overly-emotional tone. 3. Try looking for extra emphasis on one or two words, like the word "The" can be said like the, or with the E sound at the end. 4. Watch for these words; like, well, the, and, sure, etc. Someone may say the word longer than they would normally in a normal conversation. 5. Try listening for words like, "yeah, uh-huh, sure," and, "as if." 6. If whatever they're saying sounds outrageous, they may be sarcastic. 7. If none of these steps work, then you are dealing with a master of sarcasm. Take whatever they say with a grain of salt. 8. Look out on the internet as well. People who are being sarcastic on the internet (could be considered trolling) are usually clearly sarcastic. Always look for stupidity in others' posts.
Post a Comment
Read more