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Trojan Asteroid 2019 LD2
Hubble Spots Vagabond Comet Near Jupiter's Asteroids
NASA's Hubble Space Telescope snapped this image of the young comet P/2019 LD2 as it orbits near Jupiter's captured ancient asteroids, which are called Trojans. This icy object is the first comet astronomers have spotted near the Trojan population.
The Hubble view reveals a 400,000-mile-long tail of dust and gas flowing from the wayward comet's bright solid nucleus. The tail is evidence that the icy object is active, despite its great distance from the faint Sun, nearly a half-billion miles away. The tail could be driven by the release of carbon monoxide and carbon dioxide. These volatiles do not need much sunlight to heat their frozen form and convert them to gas.
The wayfaring comet was discovered in early June 2019 by the University of Hawaii's Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope.
The icy interloper is most likely one of the latest members of the so-called "bucket brigade" of comets to travel inward toward the Sun after getting kicked out of its frigid home in the Kuiper belt through interactions with the outermost giant planet, Neptune.
Located on the outskirts of our solar system, the Kuiper belt is a haven of icy, leftover debris from our planets' construction 4.6 billion years ago.
The vagabond comet is a temporary resident among Jupiter's asteroids. Computer simulations show that the unexpected guest will have a close encounter with Jupiter in roughly another two years. The massive planet will boot the comet toward the inner solar system.
This Hubble visible-light image is a combination of exposures taken April 1 and May 8, 2020, with the Wide Field Camera 3.
About the Object
- DistanceDistanceThe physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.At the time of observations, the comet was 4.02 AU from Earth (374 million miles).
About the Data
- Data DescriptionData DescriptionProposal: A description of the observations, their scientific justification, and the links to the data available in the science archive.
Science Team: The astronomers who planned the observations and analyzed the data. "PI" refers to the Principal Investigator. - InstrumentInstrumentThe science instrument used to produce the data.WFC3/UVIS
- Exposure DatesExposure DatesThe date(s) that the telescope made its observations and the total exposure time.1 April 2020 and 8 May 2020
- FiltersFiltersThe camera filters that were used in the science observations.F350LP
- Object NameObject NameA name or catalog number that astronomers use to identify an astronomical object.Trojan Asteroid 2019 LD2
- Object DescriptionObject DescriptionThe type of astronomical object.Comet
- Release DateFebruary 25, 2021
- Science ReleaseComet Makes a Pit Stop Near Jupiter’s Asteroids
- CreditNASA, ESA, STScI, Bryce Bolin (Caltech/IPAC)
This image is an exposure acquired by the WFC3 instrument on the Hubble Space Telescope. The color results from assigning the color blue to a monochromatic (grayscale) image.

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Claire Andreoli
NASA’s Goddard Space Flight Center
Greenbelt, Maryland
claire.andreoli@nasa.gov