Next month ESA will attempt to place a lander the size of a shopping trolley on a comet travelling at 55,000 kilometers an hour. With virtually no gravity to stop it bouncing off, and boulders the size of houses scattered across the landing zone, it’s a risky procedure. The potential reward of the Rosetta mission if all goes well is enormous– we should have a grandstand view as the comet’s surface starts to vapourize and eject jets of material as it approaches the Sun. It’s not the only highlight for armchair astronomers in the coming year though – we’re in for a fairly rich twelve months as far as celestial attractions go, culminating in a flyby next July of the only sizable object in the solar system that mankind has never visited, Pluto.
The Rosetta project has been 21 years in the making and the probe itself has spent over ten years merely getting to comet 67P/Churyumov-Gerasimenko, culminating in some incredibly intricate and complicated manoeuvres to place the probe in orbit around the comet. The reason it’s so important is that comets are believed to be remnants from the dawn of the solar system, formed about 4 billion years ago, so by closely observing 67P we can see what comets and by inference the earliest planets were made of. But it’s a risky project – as the comet heats up either the lander or Rosetta or both could be knocked out by erupting jets of material. Closest approach to the sun will be on 15 August 2015 and the mission is due to run until December 2015, so armchair astronomers are in for an exciting year as the comet approaches the Sun.
The next date on the celestial calendar is April 2015 when NASA’s Dawn probe will visit the biggest asteroid, Ceres, almost half the size of Pluto. Dawn has already visited the second largest asteroid, Vesta, where it made the important discovery that there was water locked in minerals beneath the surface, and which appeared to periodically erupt outwards from pits up to 200 metres deep.
In July 2015 we reach what will perhaps be the celestial highlight of the year when the New Horizons probe flies past Pluto, hopefully avoiding the small crowd of satellites that have been discovered around Pluto in recent years. What will Pluto look like? And where will New Horizons go next? The plan is for a Kuiper Belt Object, but it depends a lot on what objects are within reach.
Then in July 2016, NASA’s Juno probe will reach and go into orbit around the gas giant Jupiter, the first craft to spend time at the planet since the NASA-ESA probe Cassini was there over a decade before. Juno will focus on investigating Jupiter’s composition, atmosphere and magnetic field, aiming to distinguish between prevailing theories of its formation in the solar system as well as to understand its internal dynamics better.
We shouldn’t forget the veritable party going on at Mars though, with seven active missions in progress this year. On the surface, the Curiosity and Opportunity rovers are trundling around investigating its geology and looking for signs of past water, and above them are the Odyssey, Express and Reconnaissance orbiters, joined just last month by NASA’s MAVEN craft and the Indian Space Agency’s Mars Orbiter Mission (also known as Mangalyaan).
Mangalyaan in particular is a huge technical triumph, making India only the fourth country or country-group to have successfully sent a probe to Mars, and most remarkably doing so successfully at the first attempt, something that not even the US or Russia achieved. It is also the start of a minor flurry of missions next year by the newer space nations with China, India and Russia all planning to land probes on the Moon.
Further out the story gets even more interesting with not just India and China entering the planetary exploration game, but private enterprise too. In 2018 Inspiration Mars plans to launch two people on a 500 day return trip to Mars, and in 2023 Mars One aims to land the first human settlers on Mars. Now that really will be something to watch.