Nasa’s Hubble space telescope crossed another milestone in its space odyssey of exploration and discovery. The earth-orbiting observatory logged its one millionth science observation during a search for water in an exoplanet’s atmosphere 1,000 light-years away.
“For 21 years Hubble has been the premier space science observatory, astounding us with deeply beautiful imagery and enabling ground-breaking science across a wide spectrum of astronomical disciplines”, said Nasa administrator Charles Bolden. He piloted the space shuttle mission that carried Hubble to orbit. “The fact that Hubble met this milestone while studying a faraway planet is a remarkable reminder of its strength and legacy.”
Although Hubble is best known for its stunning imagery of the cosmos, the millionth observation is a spectroscopic measurement, where light is divided into its component colours. These colour patterns can reveal the chemical composition of cosmic sources.
Hubble’s millionth exposure is of the planet HAT-P-7b, a gas giant planet larger than Jupiter orbiting a star hotter than our sun. HAT-P-7b, also known as Kepler 2b, has been studied by Nasa’s planet-hunting Kepler observatory after it was discovered by ground-based observations. Hubble now is being used to analyse the chemical composition of the planet’s atmosphere.
“We are looking for the spectral signature of water vapour. This is an extremely precise observation and it will take months of analysis before we have an answer”, said Drake Deming of the University of Maryland and Nasa’s Goddard Space Flight Centre in Greenbelt, Md. “Hubble demonstrated it is ideally suited for characterising the atmospheres of exoplanets, and we are excited to see what this latest targeted world will reveal.” Hubble was launched April 24, 1990, aboard space shuttle’s Discovery’s STS-31 mission. Its discoveries revolutionised nearly all areas of astronomical research from planetary science to cosmology. The observatory has collected more than 50 terabytes of data to-date.
Hubble’s odometer reading includes every observation of astronomical targets since its launch and observations used to calibrate its suite of instruments.