(6178) 1986 DA
Encyclopedia
1986 DA is a 2.3-kilometre-diameter M-type
Mars-crosser
and near-Earth asteroid, notable for being significantly more radar
-reflective than other asteroid
s. It is an Amor asteroid
, which means it approaches the orbit of Earth from the outside but does not cross it.
Radar measurements suggest it is composed of nickel
and iron
and that it was derived from the center of a much larger object that experienced melting and differentiation. The observed radar albedo
was 0.58 and the optical albedo was 0.14.
This asteroid was most probably formed from a larger body through a catastrophic collision with another object. Radar measurements of this body indicate that the surface is relatively smooth on scales of less than a meter, but it is highly irregular on scales of 10–100 meters.
The delta-v
for a spacecraft rendezvous with this asteroid from low earth orbit
is 7.1 km/s.
1986 DA reached perihelion in its orbit on March 6, 2005.
Asteroid 1986 DA achieved its most notable recognition when scientists revealed that it contained over "10,000 tons of gold and 100,000 tons of platinum", or an approximate value at the time of its discovery of "$90 billion for the gold and a cool trillion dollars for the platinum, plus loose change for the asteroid's 10 billion tons of iron and a billion tons of nickel."
M-type asteroid
M-type asteroids are asteroids of partially known composition; they are moderately bright . Some, but not all, are made of nickel-iron, either pure or mixed with small amounts of stone. These are thought to be pieces of the metallic core of differentiated asteroids that were fragmented by impacts,...
Mars-crosser
Mars-crosser asteroid
A Mars-crosser is an asteroid whose orbit crosses that of Mars. The known numbered Mars-crossers are listed here. They include the two numbered Mars trojans 5261 Eureka and ....
and near-Earth asteroid, notable for being significantly more radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
-reflective than other asteroid
Asteroid
Asteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
s. It is an Amor asteroid
Amor asteroid
The Amor asteroids are a group of near-Earth asteroids named after the asteroid 1221 Amor. They approach the orbit of the Earth from beyond, but do not cross it. Most Amors do cross the orbit of Mars...
, which means it approaches the orbit of Earth from the outside but does not cross it.
Radar measurements suggest it is composed of nickel
Nickel
Nickel is a chemical element with the chemical symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile...
and iron
Iron
Iron is a chemical element with the symbol Fe and atomic number 26. It is a metal in the first transition series. It is the most common element forming the planet Earth as a whole, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust...
and that it was derived from the center of a much larger object that experienced melting and differentiation. The observed radar albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
was 0.58 and the optical albedo was 0.14.
This asteroid was most probably formed from a larger body through a catastrophic collision with another object. Radar measurements of this body indicate that the surface is relatively smooth on scales of less than a meter, but it is highly irregular on scales of 10–100 meters.
The delta-v
Delta-v
In astrodynamics a Δv or delta-v is a scalar which takes units of speed. It is a measure of the amount of "effort" that is needed to change from one trajectory to another by making an orbital maneuver....
for a spacecraft rendezvous with this asteroid from low earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
is 7.1 km/s.
1986 DA reached perihelion in its orbit on March 6, 2005.
Asteroid 1986 DA achieved its most notable recognition when scientists revealed that it contained over "10,000 tons of gold and 100,000 tons of platinum", or an approximate value at the time of its discovery of "$90 billion for the gold and a cool trillion dollars for the platinum, plus loose change for the asteroid's 10 billion tons of iron and a billion tons of nickel."