For the first time, Mercury now possesses an artificial satellite. Lead investigator Sean Solomon, Messenger's principal investigator at the Carnegie Institution of Washington, stated when the investigation landed at Mercury. "It's a great day for astronomy and for Penn State University,".
Messenger is the first spacecraft to orbit another planet. It was launched by NASA on August 03, 2004, at 10:31 a.m. EST (15:31 UTC) from Cape Canaveral Air Force Station in Florida. The probe made its closest approach to Mercury on April 18 at 7:51 a.m. EDT (11:51 UTC). During that pass, it collected 70 percent of the data expected from this mission. After this close encounter, Messenger will use its ion engine to enter a highly elliptical orbit that will take it as far as 0.4 astronomical units (about 60 million miles or 90 million kilometers) from the Sun, but only as far as 45 degrees away from the ecliptic plane. At its most distant point, it will be traveling at about 58,000 mph (93,600 km/hr). This will allow it to cover much of Mercury's surface over multiple orbits until it runs out of fuel in 2025.
In addition to studying the chemistry of the planet, Messenger should provide information about the history of Earth's nearest neighbor.
On March 18, 2011, MESSENGER became the first spacecraft to reach orbit around Mercury. In 2012, it successfully achieved its primary purpose... Messenger.
|Artist’s rendering of MESSENGER orbiting Mercury.|
|Mission type||Mercury probe|
MESSENGER is a NASA spacecraft. The MESSENGER spacecraft from NASA was the first to circle the planet Mercury. It entered orbit around our solar system's innermost planet in 2011 and terminated its mission in 2015 with a collision onto the planet's surface. More than 200,000 images of Mercury were taken by the probe. These photographs provide scientists with information about the history and evolution of this planet.
MESSENGER was built by Boeing in El Segundo, California. It launched on April 25, 2004, at 10:31 a.m. PDT (15:31 UTC) from Cape Canaveral Air Force Station, Florida, aboard a Delta-II 7925H rocket. After orbiting Earth for four months, it made its first close-up look at Mercury on May 30, 2005.
The image above was taken by MESSENGER's Digital Photography System during an orbit of Mercury on July 17, 2005. A total of 202 photos were taken that day with a resolution of 5 inches by 5 inches (13 cm by 13 cm).
This image shows a portion of Mercury's western hemisphere. The picture was taken from a distance of 498,000 miles (800,000 km) from Earth and 730 miles (1,140 km) from the center of Mercury. The image has been enhanced to make some features more visible against the dark terrain of the planet.
There are no known natural satellites of the planet. Mariner 10 passed past Mercury in 1974 and 1975, while MESSENGER, launched in 2004, orbited Mercury over 4,000 times in four years before running out of fuel and crashing on the planet's surface on April 30, 2015. The impact destroyed its mission instrumentation but not itself.
However, it is possible that an object was missed by scientists looking for evidence of other bodies orbiting Mercury. If such an object were to be found from another trajectory than that taken by Mariner 10, it might be a sign that something had crashed into Mercury.
Something also hit the planet in A.D. 861, based on calculations using data from Mariner 10 and several other missions. Scientists think this may have been another NASA spacecraft, which they call "Mercury XX". It's possible that this was an earlier attempt at reaching Mercury that failed because the vehicle ran out of fuel before it could enter orbit.
Another possibility is that it's an asteroid or comet that has been captured by Mercury's gravitational pull. This would not be the first time this has happened; the last such incident was approximately 3 million years ago when an asteroid or cometary fragment was inserted into Mercury's atmosphere where it burned up completely over Northern Africa.
Mariner 10, the first spacecraft to visit Mercury, photographed around 45 percent of the surface. MESSENGER, a NASA spacecraft, sailed past Mercury three times and orbited the planet for four years before landing on its surface. In 2018, the European Space Agency launched its first mission to investigate Mercury-BepiColombo. The mission includes a Japanese space probe and a U.S. orbiter.
The answer is no, there are no satellites orbiting Mercury.
Mercury has very strong gravitational field due to its proximity to the Sun. This means that every object on or inside of Mercury's orbit will experience gravity from both Earth and Mercury. As a result, objects such as astronauts in manned missions or debris in orbit around Mercury may be captured by the planet's gravity and moved around within it.
However, because of its small size and distant location from the Sun, escape velocity is high (about 11 km/s) and any object with enough energy can leave Mercury's orbit. An astronaut on board a spacecraft traveling at 20,000 km/h (12,500 mph), for example, would need about 4 minutes 40 seconds to leave Mercury's orbit.
It is estimated that there are several thousand objects currently trapped within Mercury's orbit, including pieces of defunct satellites and space junk. It may also contain human-made objects, such as abandoned probes from previous missions.
For more than four years, NASA's MESSENGER spacecraft orbited Mercury. Among its achievements, the mission assessed Mercury's surface composition, detailed its geological history, obtained data about its internal magnetic field, and confirmed that its polar deposits are mostly water-ice. It also discovered that ancient impacts had vaporized much of the planet's interior, leaving behind a crust only 10% as thick as Earth's.
Before MESSENGER, only images from the Mariner 10 spacecraft had been available for study of Mercury. These images showed a very different world to Earth - cold and dark with no evidence of a magnetic field. But MESSENGER's close-up observations revealed a highly dynamic planet, with many features we would not have known about otherwise. Its early studies will help inform us about how planets form and evolve.
MESSENGER was launched on April 25th, 2011 by a Delta II rocket from Cape Canaveral, Florida. It arrived at Mercury on March 18th, 2013 after an almost three years in orbit around the Sun. During its journey it collected over 75 million pieces of data which will be made available to the public after the mission ends next year.
It is expected that MESSENGER will be able to provide new information about Mercury for at least another decade after its final data drop.
Mercury exploration has a tiny position in the world's space ambitions. It is the inner planet with the least amount of exploration. As of 2015, the only missions that had performed close observations of Mercury were the Mariner 10 and MESSENGER missions. The MESSENGER probe was the first to circle Mercury. Its mission ended in 2018.
Did you know that Venus has volcanoes? No, neither did we. But now there is evidence of active volcanism on Venus. Many scientists believe this proves that water once existed on Venus even though it is now extremely hot. This discovery was made in 1992 by one of our own satellites! The Magellan spacecraft discovered large regions where the surface appears to have been modified by erosion or volcanic activity. These areas are called maria (mah-REE-a). The name comes from the Spanish word for sea, mar.
Venus has been explored by several different types of spacecraft over the years. Two Soviet landers and two American orbiters have also flown by Venus. None of these missions found evidence of life but that might change if NASA's new Venus Rover launches next year. It will be the first ever sent to another planet!
Comets are objects composed of ice and dust that orbit the Sun. They are visible as a fuzzy ball when viewed with the naked eye. Over time, sunlight breaks down organic material in comets' cores into simpler substances such as carbon dioxide and ammonia.