#Open journalism No news is bad news

Your contributions will help us continue to deliver the stories that are important to you

Support The Journal
Dublin: 18°C Tuesday 28 June 2022

Rosetta spacecraft reaches comet it's been chasing for ten years

For today, Rosetta will travel alongside the comet but will later start its orbits.

Updated 11.08

Source: ESA

EUROPEAN SCIENTISTS WERE on tenterhooks this morning as they prepared for a historic rendezvous between a comet and a space probe after a 10-year, six billion-kilometre chase through the Solar System.

The scout Rosetta finally arrived at Comet 67P/Churyumov-Gerasimenko in deep space at around 10am GMT, and has become the first envoy of Man to orbit one of these wanderers of the Solar System, they said.

final approach The spacecraft's final approach to the comet... Source: ESA

If all goes well, the mission in November will carry out the first landing on a comet. Rosetta will send a robot chemistry lab to the surface to delve into a theory that comets hold the key to understanding how our star system formed.

Orbital entry was triggered at around 10am by a small firing of Rosetta’s thrusters, lasting just six minutes and 26 seconds.

“This burn will tip Rosetta into the first leg of a series of three-legged triangular paths about the comet,” the ESA said.

For today, Rosetta will travel alongside the comet but will later start its orbits.

The “pyramidal” orbits will put the craft at a height of about 100 kilometres above the comet, said Sylvain Lodiot, Rosetta’s flight operations manager. Each leg of the triangle will be around 100 kilometres and take Rosetta between three and four days to complete.

This arrival marks a key moment of the boldest project ever undertaken by ESA – a 1.3-billion-euro investigation into one of enigmas of the Solar System.

Comets are believed by astrophysicists to be ancient ice and dust left from the building of the Solar System around 4.6 billion years ago. This cosmic rubble is the oldest, least touched material in our stellar neighbourhood.

Understanding its chemical ID and physical composition will give insights into how the planets coalesced after the Sun flared into light, it is hoped.

It could also determine the fate of a theory called “pan-spermia,” which suggests comets, by smashing into the infant Earth, sowed our home with water and precious organic molecules, providing us with a kickstart for life.

Navigational feat 

Getting there has been an unprecedented navigational exploit.

Source: European Space Agency, ESA/YouTube

Launched in March 2004, the three-tonne craft has had to make four flybys of Mars and Earth, using their gravitational force as a slingshot to build up speed.

It then entered a 31-month hibernation as light from the distant Sun became too weak for its solar panels. That period ended in January with a wake-up call sent from Earth.

The spacecraft is named after the famous stone, now in the British Museum, that explained Egyptian hieroglyphics, while its payload Philae is named after an obelisk that in turn helped decipher the Rosetta stone.

The four-kilometre comet is named after two Ukrainian astronomers who first spotted it in 1969.

- © AFP 2014 with additional reporting by Michelle Hennessy.

Related: ‘World Cup final’ event as 6 billion km comet-chaser nears its target>

About the author:


Read next: