Thursday, May 12, 2016

Hubble Catches Views of a Jet Rotating with Comet 252P/LINEAR

Comet 252P/LINEAR
 Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)


Introduction: For thousands of years, humans have recorded sightings of mysterious comets sweeping across the nighttime skies. These celestial wanderers, "snowballs" of dust and ice, are swift-moving visitors from the cold depths of space. Some of them periodically visit the inner solar system during their journeys around the sun.

Astronomers using NASA's Hubble Space Telescope captured images of Comet 252P/LINEAR just after it swept by Earth on March 21. The visit was one of the closest encounters between a comet and our planet. The comet traveled within 3.3 million miles of Earth, or about 14 times the distance between our planet and the moon. The images reveal a narrow, well-defined jet of dust ejected by the comet's icy, fragile nucleus. These observations also represent the closest celestial object Hubble has observed, other than the moon.

The comet will return to the inner solar system again in 2021.



About image: This sequence of images taken by NASA's Hubble Space Telescope shows Comet 252P/LINEAR as it passed by Earth. The visit was one of the closest encounters between a comet and our planet.

The images were taken on April 4, 2016, roughly two weeks after the icy visitor made its closest approach to Earth on March 21. The comet traveled within 3.3 million miles of Earth, or about 14 times the distance between our planet and the moon. These observations also represent the closest celestial object Hubble has observed, other than the moon.

The images reveal a narrow, well-defined jet of dust ejected by the comet's icy, fragile nucleus. The nucleus is too small for Hubble to resolve. Astronomers estimate that it is less than one mile across. A comet produces jets of material as it travels close to the sun in its orbit. Sunlight warms ices in a comet's nucleus, resulting in large amounts of dust and gas being ejected, sometimes in the form of jets. The jet in the Hubble images is illuminated by sunlight.

The jet also appears to change direction in the images, which is evidence that the comet's nucleus is spinning.

The spinning nucleus makes the jet appear to rotate like the water jet from a rotating lawn sprinkler. The images underscore the dynamics and volatility of a comet's fragile nucleus.

Comet 252P/LINEAR is traveling away from Earth and the sun; its orbit will bring it back to the inner solar system in 2021, but not anywhere close to Earth.

These visible-light images were taken with Hubble's Wide Field Camera 3.


For more information, contact:

Donna Weaver / Ray Villard
Space Telescope Science Institute, Baltimore, Maryland
410-338-4493 / 410-338-4514
dweaver@stsci.edu / villard@stsci.edu

Jian-Yang Li
Planetary Science Institute, Tucson, Arizona
571-488-9999
jyli@psi.edu

 
Source: HubbleSite