Cases of historical encounters with comets

November 4, 2010 will forever be noted in the history textbooks of the country as the day a spacecraft approached the comet Hartley 2 within a distance of 700 km.

Historical encounters with comets

However, Hartley 2 is not the only goal that NASA's EPOXI ships .

In 2005, along with the same spacecraft, called Deep Impact , not only flew across the comet Tempel 1 but also fired a 370 kg copper core device at the comet's body with a collision speed of 16 km / s. , creating a column of high smoke in space. Ground scientists studied this smoke column thanks to the camera system on Deep Impact.

Later, the probe was renamed EPOXI and redirected to comet 2: Hartley 2.

EPOXI / Deep Impact is probably the first probe to be reused for two different comet studies, but this is not the first ship to take on the mysterious mission of approaching 'dirty snowballs'. .

So far, with the help of space robots , humans have repeatedly been able to 'meet' comets in close proximity. The following are special events:

Halley (1986)

As the most famous comet in history, Halley was the main target of space agencies in 1986 when the comet performed the 75 to 76 cycle through the solar system.

The comet science is still an area that is still being explored, but in 1986, the scientific community knew almost nothing about the object wandering indefinitely in the universe.

In October of that year, the Giotto probe of the European Space Agency (ESA) was sent to meet the 15 km long comet Halley. The half-ton probe was within 600 kilometers of Halley from the comet core, and captured the first images of airflow from individual regions on the comet surface.

This is also the mission to confirm the theory of ' dirty snowball' : a blend of easy sublimation ice and dust.

However, Giotto could only approach the famous comet thanks to the help of Halley Armada, a number of designated international spacecraft taking on the task of observing this rare event. Giotto captured the image at the nearest distance, but two Russian / French ships (Vega 1 and 2) and two Japanese ships (Suisei and Sakigake) observed from a distance.

Borrelly (2001)

At half the size of Halley, Borrelly comet was discovered to have similar characteristics with a famous relative.

Borrelly's kernel also has a potato shape and is very dark. If Halley's nucleus reflects 4% of incoming light, Borrelly's core has a reflectivity of 2.4 - 3%, while bitumen is 7%. According to the observation of Deep Space 1 (NASA) on September 22, 2001, the tail of dust escapes from cracks in the comet's core, where volatile substances 'face up' to sunlight, loading Steam the dust layer into the universe. The approach distance of Deep Space 1 was 3,417 km.

Wild (2004)

Comet Wild 2 underwent a spectacular change in 1974. According to experts' calculations, due to moving too close to Jupiter that year, the comet was 5 km wide and turned into a long orbit. 6 years compared to 43 years before being "bullied" by Jupiter.

This change has turned Wild 2 into an ideal target for NASA's Stardust mission.

On April 4, 2004, the Stardust caught up with Wild 2 and moved so close that it could collect dust particles escaping from the tip of the comet. The image below was taken at a distance of less than 240 km from the probe to Wild 2.

Stardust specimens were safely returned to Earth on January 15, 2006. These molecular particles continue to provide a more detailed view of comets' organic compounds.

Interestingly, Stardust has continued to be assigned a new mission after successfully completing the initial mission. In 2011, she will be able to meet the comet Tempel 1 and analyze the impact crater left by the Deep Impact on this comet surface.

Tempel (2005)

As mentioned above, NASA's Deep Impact vessel touched the comet of Tempel 1, about 8 km across in 2005.

On July 4, 2005, the probe from the probe created a hole 30 meters deep, 100 meters wide on the surface of Tempel 1.

This intentional collision can be observed from the earth.

Next year, it is the Stardust's turn to take on the task of studying collisions.

67P / Churyumov-Gerasimenko (2014)

On November 12, for the first time in history, the ship Philae successfully landed on the surface of the star Broom 67P / Churyumov-Gerasimenko (67P / CG).

Philae with a robot-like design

Philae is an exploration robot ship whose mission is to study the planet is believed to hold secrets about the origin of the Solar System and possibly life on Earth 4.6 billion years ago.

To carry out this historic mission, the Philae and Rosetta's mother ship had to travel 6.4 billion km long. And after 10 years of launching from Earth (March 2, 2004), the ship 67P / CG successfully reached its destination on November 12, 2014 after being separated from the mother ship Rosetta 7 hours earlier.

The Philippe exploration ship successfully landed on the Comet