2011 MD is a bright micro-

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

, classified as

near-Earth object A near-Earth object (NEO) is any small Solar System body whose orbit brings it into proximity with Earth. By convention, a Solar System body is a NEO if its closest approach to the Sun (perihelion) is less than 1.3 astronomical units (AU). ...

of the

Apollo Apollo, grc, Ἀπόλλωνος, Apóllōnos, label=genitive , ; , grc-dor, Ἀπέλλων, Apéllōn, ; grc, Ἀπείλων, Apeílōn, label=Arcadocypriot Greek, ; grc-aeo, Ἄπλουν, Áploun, la, Apollō, la, Apollinis, label= ...

and

Amor group Amor Group was Scotland's largest independent business technology company before being acquired by Lockheed Martin in September 2013. The business was formed after a £28 million management buyout of Glasgow based Real Time Engineering Ltd. an ...

, respectively. On 27 June 2011, at around 17:00 UTC (13:00 EDT), the object passed exceptionally close to Earth's surface at a distance of approximately , roughly the diameter of the Earth.

Description

Although was initially believed to be

space junk Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecr ...

, subsequent observations confirmed that it is an asteroid. A few hours before the asteroid's nearest approach in 2011, it appeared close to the Sun, so observations were possible for only a brief period. Backyard astronomers were able to observe it with telescopes from Australia, southern Africa, and the Americas. was discovered on 22 June 2011, by astronomers of the

Lincoln Near-Earth Asteroid Research The Lincoln Near-Earth Asteroid Research (LINEAR) project is a collaboration of the United States Air Force, NASA, and the Massachusetts Institute of Technology's Lincoln Laboratory for the systematic detection and tracking of near-Earth objects ...

(LINEAR) at the U.S.

Lincoln Laboratory Experimental Test Site The MIT Lincoln Laboratory, located in Lexington, Massachusetts, is a United States Department of Defense federally funded research and development center chartered to apply advanced technology to problems of national security. Research and dev ...

in Socorro, New Mexico, by a pair of robotic telescopes. According to original rough estimates, the asteroid's length was between . However, according to the more recent

absolute magnitude Absolute magnitude () is a measure of the luminosity of a celestial object on an inverse Logarithmic scale, logarithmic Magnitude (astronomy), astronomical magnitude scale. An object's absolute magnitude is defined to be equal to the apparent mag ...

(H) measurement of 28.1 and its albedo of 0.3, the asteroid is closer to 6 meters or 20 feet in diameter. Emily Baldwin of ''

Astronomy Now ''Astronomy Now'' is a monthly British magazine on astronomy and space. According to the Royal Astronomical Society, ''Astronomy Now'' is the "principal amateur astronomy magazine in Britain" with a reputed circulation of 24,000. The magazine f ...

'' said that there was no threat of collision, and should the asteroid enter

Earth's atmosphere The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing for ...

, it would "mostly burn up in a brilliant fireball, possibly scattering a few

meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...

s", causing no likely harm to life or property on the ground. The 27 June 2011 close approach to Earth increased the orbital period of from 380 days to 396 days. During close approach the asteroid passed Earth at a relative speed of 6.7 km/s with a

geocentric In astronomy, the geocentric model (also known as geocentrism, often exemplified specifically by the Ptolemaic system) is a superseded description of the Universe with Earth at the center. Under most geocentric models, the Sun, Moon, stars, an ...

eccentricity of 1.1. was observed by the

Spitzer Space Telescope The Spitzer Space Telescope, formerly the Space Infrared Telescope Facility (SIRTF), was an infrared space telescope launched in 2003. Operations ended on 30 January 2020. Spitzer was the third space telescope dedicated to infrared astronomy, f ...

in February 2014 and estimated to be in diameter. The asteroid is a

porous Porosity or void fraction is a measure of the void (i.e. "empty") spaces in a material, and is a fraction of the volume of voids over the total volume, between 0 and 1, or as a percentage between 0% and 100%. Strictly speaking, some tests measure ...

rubble pile In astronomy, a rubble pile is a celestial body that is not a monolith, consisting instead of numerous pieces of rock that have coalesced under the influence of gravity. Rubble piles have low density because there are large cavities between the ...

with a density similar to water. On 19 June 2014, NASA reported that asteroid was a prime candidate for

capture Capture may refer to: *Asteroid capture, a phenomenon in which an asteroid enters a stable orbit around another body *Capture, a software for lighting design, documentation and visualisation *"Capture" a song by Simon Townshend *Capture (band), an ...

by the

Asteroid Redirect Mission The Asteroid Redirect Mission (ARM), also known as the Asteroid Retrieval and Utilization (ARU) mission and the Asteroid Initiative, was a space mission proposed by NASA in 2013; the mission was later cancelled. The Asteroid Retrieval Robotic ...

(ARM) in the early 2020s.

Gallery

References

External links

Encounter animations
(Pasquale Tricarico) * * * {{DEFAULTSORT:2011 MD # # Minor planet object articles (unnumbered) # 20110627 20110622 Near-Earth objects in 2024

Description

Gallery

See also

References

External links