Shop Windows to the Universe

Arches National Park Geology Tour provides an extensive, visually rich description of the geology of Arches, by Deborah Ragland, Ph.D. See our DVD collection.
Asteroid Lutetia as viewed by the Rosetta spacecraft on July 10, 2010.
Click on image for full size

Asteroid Lutetia

Lutetia is a medium-sized asteroid. It orbits the Sun in the main asteroid belt between the planets Mars and Jupiter. Its official name is "21 Lutetia" because it was the 21st asteroid discovered. Lutetia was discovered by Hermann Goldschmidt from the balcony of his apartment in Paris in 1852. Lutetia is the Latin name for Paris.

This lumpy object is about 96 km (60 miles) in diameter. It isn't a perfect sphere, though. Lutetia is 132 km (82 miles) across one way, but only about 76 km (47 miles) long in another direction.

Astronomers aren't quite sure what Lutetia is made of. It may have more metal in it than most asteroids. However, some observations of Lutetia show that it is mostly rock, like most other asteroids. The material that an asteroid is made of gives us clues about how it formed and what has happened to it over the history of the Solar System.

The European space probe Rosetta flew past Lutetia in July 2010. Rosetta gave us our first good look at the asteroid. Lutetia is the largest asteroid visited by a spacecraft so far. Rosetta was zooming along at a speed of 15 km/s (9 miles/sec or more than 33,000 mph) when it flew by Lutetia! Rosetta sent some great pictures and lots of other data back to Earth. After its visit to Lutetia, Rosetta continued on its long journey to land on a comet in 2014.

Last modified July 15, 2010 by Randy Russell.

Shop Windows to the Universe Science Store!

Learn about Earth and space science, and have fun while doing it! The games section of our online store includes a climate change card game and the Traveling Nitrogen game!

Windows to the Universe Community



You might also be interested in:

Traveling Nitrogen Classroom Activity Kit

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Solar System Formation

Scientists believe that the solar system was formed when a cloud of gas and dust in space was disturbed, maybe by the explosion of a nearby star (called a supernova). This explosion made waves in space...more

The Solar System

The solar system is made up of the Sun, the // Call the planets count function defined in the document head print_planet_count('planets'); planets and // Call the planets count function defined in the...more

Rosetta Flyby of Asteroid Lutetia

Rosetta is a European space probe. It was launched in 2004. Its main mission is to fly to a comet and land on it. Along the way it has flown by two asteroids. In July 2010 it flew by an asteroid named...more

Comet Churyumov-Gerasimenko

Comet 67P/Churyumov-Gerasimenko was discovered in 1969 by Klim Churyumov and Svetlana Gerasimenko. The comet orbits the Sun once every 6.57 years. Its orbit brings it closer to the Sun than Mars at the...more

Asteroid Toutatis

Toutatis is a very strange asteroid. It has a strange shape, and it spins in a very unusual way. Sometimes Toutatis comes close to Earth. This asteroid is shaped sort of like a potato. Its size is 1.92...more

Asteroid Lutetia

Lutetia is a medium-sized asteroid. It orbits the Sun in the main asteroid belt between the planets Mars and Jupiter. Its official name is "21 Lutetia" because it was the 21st asteroid discovered. Lutetia...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA