This diagram shows the shape and size of the orbit of Comet Wild 2. The comet's orbit is shown in aqua. The orbits of Jupiter, Mars, and Earth are also shown.
Click on image for full size
Comet Wild 2
Comet Wild 2 is a short-period comet that
orbits the Sun once
every 6.39 years. A Swiss astronomer
named Paul Wild discovered it on January 6, 1978. Wild 2 is
pronounced "Vilt 2". The comet comes about
Sun as the planet Mars, and loops about
as far away as the planet Jupiter.
The comet's nucleus is about 5 km (3 miles) across, so Wild 2 is not an especially large comet.
Astronomers routinely calculate the positions of newly discovered comets
at earlier times to make sure someone hasn't re-discovered a previously
known comet. The scientists made a surprising discovery when they calculated
the orbit of Wild 2 backwards
to the years
that on September 10, 1974, the comet passed very close to Jupiter and
had its orbit substantially altered by that giant planet's gravity. Before
1974, Wild's orbit was in the outer solar system, ranging between Jupiter's
and Uranus' distance from the Sun.
So, until recently, Wild 2 had never come very close to the Sun.
Since Wild 2 has only taken a few swings
near the heat of the Sun, most
of its ices have not been melted away. Apparently Wild 2 has been kept
in cold storage since the early days of our Solar
System, which makes
it a very interesting comet to study. Studies of Wild 2 may help scientists
understand what the materials that originally formed our Solar System
Because Wild 2 (which is also known as Comet 81P/Wild 2) is in such a pristine condition, scientists chose it as the target of a space mission called Stardust. The Stardust spacecraft flew by Wild 2 in January 2004 and captured some tiny particles from the comet. It will return
those particles to Earth in 2006, giving scientists their first sample of cometary materials that may shed light on the history and evolution of our Solar System. Stardust also shot the best images ever taken of the nucleus of a comet during its flyby.
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, ranging from seismology
, rocks and minerals
, and Earth system science
You might also be interested in:
The image on this page shows the best views we've ever had (so far) of the nucleus of a comet. On January 2, 2004, the Stardust spacecraft flew past Comet Wild 2 at a relative speed of roughly six kilometers...more
Comets are disturbed from their orbits in the Oort Cloud and begin a passage into the solar system, spinning and tumbling as they come. The trajectory which they acquire can be hyperbolic, parabolic, or...more
NASA's Stardust mission was the first spacecraft to collect samples of material directly from a comet and return them to Earth. Stardust was launched by a Delta 2 rocket from Cape Canaveral Air Station,...more
Scientists believe that the solar system was for med when a cloud of gas and dust in space was disturbed, maybe by the supernova of a nearby star. Shock waves from the explosion compressed the cloud of...more
In August 2009, scientists reported finding a type of amino acid in a sample returned from a comet. Amino acids are the building-blocks of proteins, one of the key molecules in living creatures. The comet...more
Comet Wild 2 is a short-period comet that orbits the Sun once every 6.39 years. A Swiss astronomer named Paul Wild discovered it on January 6, 1978. Wild 2 is pronounced "Vilt 2". The comet comes about...more
Hale-Bopp continues to offer surprises as astronomers study the comet. Using the Hubble Space Telescope and the International Ultraviolet Explorer, astronomers have found that their are distinctly different...more