History of Asteroid in Timeline

Asteroids are minor planets orbiting within the inner Solar System or co-orbital with Jupiter, larger than meteoroids but not planets or identified comets. They are rocky, metallic, or icy bodies without atmospheres, categorized as C-type, M-type, or S-type based on composition. Asteroid size and shape vary greatly, from small rubble piles to the dwarf planet Ceres, which is almost 1000 km in diameter. Comets are distinguished by their coma when warmed by solar radiation, though a continuum exists between the two.

1914: Asteroid designations with Greek letters

In 1914, designations included year plus a Greek letter.

1918: Hirayama families first recognized

In 1918, Kiyotsugu Hirayama first recognized main belt families of asteroids.

1925: Simple chronological numbering system established

In 1925, a simple chronological numbering system was established.

1937: Hermes Approaches Earth

In 1937, asteroid 69230 Hermes approached within 0.005 AU of Earth, raising awareness of potential Earth impacts.

1967: Project Icarus Designed

In 1967, "Project Icarus" was one of the first projects designed as a contingency plan in case of collision with 1566 Icarus, relying on Saturn V rockets and nuclear warheads.

1975: Asteroid taxonomic system developed

In 1975, an asteroid taxonomic system based on color, albedo, and spectral shape was developed.

1977: Discovery of 2060 Chiron

In 1977, 2060 Chiron was discovered, representing the first small body found to permanently reside further out than Jupiter.

1979: 7968 Elst–Pizarro Discovered

In 1979, the asteroid 7968 Elst-Pizarro was discovered, initially classified as an asteroid.

1984: Tholen classification proposed

In 1984, the Tholen classification was proposed by David J. Tholen.

1990: Discovery of Acfer 049 meteorite in Algeria

In 1990, the Acfer 049 meteorite was discovered in Algeria.

1991: First Asteroid Close-Up: Gaspra

In 1991, 951 Gaspra became the first asteroid to be photographed in close-up by the Galileo probe.

1992: Discovery of 15760 Albion

In 1992, 15760 Albion, the first object beyond Neptune (other than Pluto), was discovered.

1993: Galileo Images Ida and Dactyl

In 1993, the Galileo probe imaged 243 Ida and its moon Dactyl.

1994: Comet Shoemaker-Levy 9 Crashes into Jupiter

In 1994, the observation of Comet Shoemaker-Levy 9 crashing into Jupiter increased concerns about impact events.

1996: Elst–Pizarro found to have a tail

In 1996, Eric Elst and Guido Pizarro discovered that 7968 Elst-Pizarro had a tail, leading to its cometary designation as 133P/Elst-Pizarro.

1997: NEAR Shoemaker Photographs Mathilde

In 1997, NASA's NEAR Shoemaker photographed asteroid 253 Mathilde.

1998: Provisional designation example

In 1998, an example of provisional designation was described, with the object 1998 FJ74 receiving a provisional designation.

1999: Deep Space 1 Visits Braille

In 1999, Deep Space 1 briefly visited asteroid 9969 Braille while en route to other destinations.

2001: NEAR Shoemaker Lands on Eros

In 2001, NEAR Shoemaker became the first spacecraft to successfully orbit and land on asteroid 433 Eros.

2002: Example of horseshoe orbit: 2002 AA29

In 2002, 2002 AA29 was used as an example of an asteroid with an unusual horseshoe orbit.

2002: Stardust Visits Annefrank

In 2002, Stardust briefly visited asteroid 5535 Annefrank while en route to other destinations.

2002: Example provisional designation (2002 AT4)

In 2002, an example of an asteroid's provisional designation, such as 2002 AT4, was described.

2002: SMASS classification developed

In 2002, the Small Main-Belt Asteroid Spectroscopic Survey resulted in a modified version of the Tholen taxonomy with 24 different types.

November 2005: Hayabusa Studies Itokawa

From September to November 2005, the Japanese Hayabusa probe studied asteroid 25143 Itokawa in detail.

2006: Main-belt comets designated

In 2006, main-belt comets (MBCs) were originally designated by astronomers David Jewitt and Henry Hsieh.

2006: IAU creates dwarf planet class

In 2006, the IAU created the class of dwarf planets for the largest minor planets, and Ceres was placed in this category.

2006: IAU introduces 'small Solar System body' term

In 2006, the International Astronomical Union (IAU) introduced the term 'small Solar System body' to include asteroids, comets, and other recently discovered classes.

2007: Dawn Spacecraft Launched

In 2007, NASA launched the Dawn spacecraft, which later orbited 4 Vesta and observed Ceres.

2008: Rosetta Probe Visits Šteins and Lutetia

In 2008, the Rosetta probe briefly visited asteroids 2867 Šteins and 21 Lutetia while en route to other destinations.

2009: Confirmation of water ice on 24 Themis

In 2009, the presence of water ice was confirmed on the surface of the asteroid 24 Themis using NASA's Infrared Telescope Facility.

June 2010: Hayabusa Returns Samples to Earth

On 13 June 2010, Hayabusa returned samples from the surface of asteroid 25143 Itokawa to Earth, marking the first asteroid sample-return mission.

August 2011: Report suggests DNA and RNA components may have formed on asteroids and comets

In August 2011, a report suggested that DNA and RNA components may have formed on asteroids and comets.

2011: Estimated Discovery Rate of Near-Earth Asteroids

As of 2011, estimates suggest that 89% to 96% of near-Earth asteroids one kilometer or larger in diameter had been discovered.

2012: Chang'e 2 Flies by Toutatis

In 2012, China's lunar orbiter Chang'e 2 flew within 3.2 km of asteroid 4179 Toutatis.

October 2013: Water detected on extrasolar body

In October 2013, water was detected on an extrasolar body (asteroid orbiting the white dwarf GD 61) for the first time.

2013: NASA Requires Preparation Time for Asteroid Interception

According to expert testimony in the United States Congress in 2013, NASA would require at least five years of preparation before a mission to intercept an asteroid could be launched.

January 2014: Detection of water vapor on Ceres

On 22 January 2014, ESA scientists reported the definitive detection of water vapor on Ceres.

2014: Hayabusa2 Launched

In 2014, JAXA launched Hayabusa2, a probe targeting asteroid 162173 Ryugu.

2016: OSIRIS-REx Launched

In 2016, NASA launched the OSIRIS-REx mission to asteroid 101955 Bennu.

2017: Observations of Hygiea

In 2017, observations were taken with the Very Large Telescope's SPHERE imager on Hygiea.

2017: Discovery of moons around 3122 Florence

In 2017, radar imaging discovered that the asteroid 3122 Florence has two moons.

June 2018: National Near-Earth Object Preparedness Strategy Action Plan

In June 2018, the National Science and Technology Council warned about the United States' lack of preparedness for an asteroid impact and released the "National Near-Earth Object Preparedness Strategy Action Plan".