NASA has launched a rocket set for Mars to study the red planet's atmosphere.
The Maven spacecraft is due to reach Mars next Autumn following a journey of more than 440 million miles.
Scientists want to unravel the mystery of the planet's drastic radical climate change, with Mars being warm and wet in its first billion years to cold and dry today.
The mission, which has cost $671 million (£417m), is NASA's 21st to the red planet since the 1960s but it is the first dedicated to studying the Martian upper atmosphere.
India has successfully launched a controversial space rocket which it hopes to use to reach Mars.Read the full story ›
India's successful launch of an unmanned satellite to Mars will be a big boost for morale for the South Asian country, one of India's leading lunar scientists told the BBC.
As the mission blasted off from Chennai, in the east of the world's second most populous country, SK Shivakumar, director of the Indian Space Research Organisation (ISRO) in Bangalore said:
"National pride is important. If the Mars mission succeeds, it will be a big morale booster for India. We are not in a space race."
India has successfully launches its first rocket to Mars, aiming to put a satellite in orbit around the planet at a lower cost than previous missions, thus potentially positioning the nation as a budget player in the global space race.
The mission is considerably cheaper than previous missions by the United States, Europe and Russia. Costing 4.5 billion rupees - (or approximately just £45.7 million) it is a fraction of the cost of an average NASA satellite mission.
However the mission has attracted criticism due to the high levels of poverty, malnutrition and power shortages suffered by millions across the country.
The UK currently gives India £280 million a year in financial aid, but this will end in 2015.
India's space agency has launched it first mission to Mars from the Satish Dhawan Space Centre in Sirharikota, near Chennai.
India's space agency to is counting down to launch its first ever rocket to Mars this morning.
Indian Space Research Organisation (ISRO) scientists have said the mission is primarily aimed at testing the best technologies to fly and orbit and communicate from the Red Planet.
If the mission is successful, and the satellite orbits the Red Planet, India's space agency will become the fourth in the world, after the US, Russia and Europe, to undertake a successful Mars mission.
The 56-hour countdown to launch started on Sunday.
Today's mission follows India's successful 2008-2009 Chandrayaan-1 moon probe, which discovered water molecules in the lunar soil.
India is counting down to its maiden voyage to Mars later today with its unmanned orbiter Mangalyaan, aka Mars Orbiter Mission.
It will take 11 months for the aircraft to reach the Red Planet, where it will conduct "meaningful scientific experiments" according to K Radhakrishnan, chair of the Indian Space Research Organisation.
Among the Mars Orbiter Mission's ambitious goals is a search for methane in the Martian atmosphere. On Earth, the chemical is strongly tied to life.
Mars has been identified as the "best bet" for human life when soaring temperatures on Earth make it inhabitable.Read the full story ›
The evidence "seems to be building that we are actually all Martians" and "that life started on Mars and came to Earth on a rock," according to a scientist from The Westheimer Institute for Science and Technology in the US.
Professor Steven Benner said, "It's lucky that we ended up here nevertheless, as certainly Earth has been the better of the two planets for sustaining life. If our hypothetical Martian ancestors had remained on Mars, there might not have been a story to tell."
Prof Benner told the Goldschmidt 2013 conference in Italy that the oxidised mineral form of the element molybdenum, "couldn't have been available on Earth at the time life first began, because three billion years ago the surface of the Earth had very little oxygen, but Mars did".
"It's yet another piece of evidence which makes it more likely life came to Earth on a Martian meteorite, rather than starting on this planet," he added.