Explorations in 2012
- March 27
- The Cassini spacecraft made one of its closest approaches yet to Enceladus, an icy moon of Saturn, at a distance of 46 miles (74 km). The craft studied plumes of water that shoot into space from the moon’s south pole. It also photographed the Sun and Earth as they disappeared behind Enceladus.
- May 19
- Astronomers watched a small piece of the solar system as it swung about a half-million miles from Earth. Asteroid 2010 KK37 made the closest approach to Earth this year of any asteroid yet discovered. The chunk of rock, which is probably about the size of a small office building, was discovered in 2010, just two days after its last close approach to Earth. Although it missed us by a wide margin, scientists tracked it carefully to refine its orbit and determine if it could collide with Earth in the coming decades.
- June 13
- An X-ray observatory designed to conduct a census of black holes launched from a Pacific island. The Nuclear Spectroscopic Telescope Array (NuStar) also will look at “jets” of charged particles squirting away from supermassive black holes and study the radioactive debris from supernova explosions to learn how chemical elements are created and distributed by the blasts.
- August 5
- The Curiosity rover, also known as Mars Science Laboratory, is scheduled to land in Gale Crater, a basin that shows signs of an ancient river delta and other evidence of water in the distant past. The nuclear-powered rover will use an on-board chemical laboratory and a rock-vaporizing laser to analyze the rocks and soil to determine if the region is or was habitable.
- August 25
- After a year studying the asteroid Vesta, the Dawn spacecraft will leave orbit and head toward the largest asteroid, Ceres. It will arrive at Ceres in 2015.
|Mars Reconnaissance Orbiter||Mars||2006|
|Lunar Reconnaissance Orbiter||Moon||2009|
Have we visited all the planets in the solar system?
Yes, space probes have visited all of the eight official planets of the solar system.
Here is a listing of the planet visited, most recent spacecraft, and year of visit (or year the mission ended):
- Mercury -- Messenger, currently in orbit
- Venus -- Venus Express, currently in orbit
- Mars -- Mars Reconnaissance Orbiter, currently in orbit
- Jupiter -- New Horizons, 2007
- Saturn -- Cassini, currently in orbit
- Uranus -- Voyager 2, 1986
- Neptune -- Voyager 2, 1989
Are there plans to return to the Moon?
President Barack Obama canceled NASA's effort to return astronauts to the Moon by 2020, so no new American Moon missions are likely. China has indicated an interest in sending its own explorers, known as taikonauts, to the Moon in the next decade or so.
In preparation for future manned exploration, the Space Agency had launched several robotic missions to map potential landing sites, map mineral resources, and hunt for possible water at the lunar poles. Future missions in this effort are likely to be cut as well.
Will we ever visit other stars?
The prospects for interstellar travel are quite daunting, primarily because stars are so incredibly far away. The nearest star lies more than 24 trillion miles away. At the fastest speed our spacecraft currently attain -- around 100,000 miles an hour or so -- it would take almost 28,000 years to get there. Even at only five percent of the speed of light (an unimaginable engineering feat of almost 34 million miles an hour), the trip would still take almost 82 years, with an equally lengthy return trip.
Our best bet may be to build an enormous colony-type spacecraft capable of sustaining a crew for the decades necessary to reach even the nearest stars. Others believe the distance problem may be avoidable altogether through some exotic twist of physics, such as traveling through a wormhole. While either of these plans might seem unlikely at the present, hope springs eternal among scientists and astronomers. Given adequate time and resources, perhaps an interstellar journey does in fact lie in our future.