NASA lands nuclear-powered, laser-armed, one-tonne rover on Mars

The Curiosity rover has been travelling for 10 months and made a safe touchdown this morning.

At 6:30am BST, NASA's Curiosity rover touched down on Mars, making it the seventh successful attempt to land a man-made object on the planet, and the largest such object yet.

Following its launch from Cape Canaveral in November last year, the mission has covered the 563 million kilometer distance without concern, but the most dangerous aspect of the trip was always going to be the last seven minutes of the descent to Mars. The Martian atmosphere is thin enough that it isn't capable of slowing objects travelling at interplanetary velocity down enough for them to make a safe landing, while being thick enough that the friction is capable of doing serious damage to an unprotected craft.

Once the rover hit the atmosphere, it had to execute a complicated series of manouvers, first deploying a massive parachute, then rocket thrusters, and then, at the very end, hovering just above the surface and lowering the car-sized rover down on nylon strings. And it had to do all of this without any aid from the control room on Earth, due to the 14 minutes it takes for radio signals from Mars to reach earth. So by the time we heard that the rover had hit the atmosphere, it had actually been sitting on the planet – dead or alive – for seven minutes.

NASA's video explaining the "seven minutes of terror" – unfortunately officially called "EDL", for "entry, descending, landing" – conveys the sheer scale of the challenge:

Now that it has arrived, the rover's first task is to explore Gale crater, its landing site. The crater contains a number of interesting geological features, including what appears to be a 5km high mountain formed out of sedimentary rock, which would make it one of the largest artifacts of running water on Mars.

But that preliminary mission is unlikely to be the rover's only one. NASA's increasingly successful missions to send rovers to Mars have been typified by the flexibility which the mobile design offers. The Pathfinder mission, which deposited a lander (a stationary craft) and a rover (named Sojourner) on Mars in 1997, was intended to last a week to a month, but ended up returning usable data for three. The follow-up rovers, Spirit and Opportunity, landed in 2004 with 90 days of planned experiments. Spirit eventually got stuck in late 2009 and stopped sending signals back to Earth in 2010, while its twin Opportunity is still active, 3,026 days after its mission was supposed to end.

But Curiosity is a different scale of mission – literally. While Sojourner was 65cm long and weighed 10.5kg, and Spirit and Opportunity 1.6m and 180kg, Curiosity is over 3m long and weighs almost a tonne. Rather than being powered by solar panels, which runs the risk of outages during dust storms and the Martian night, it contains a plutonium battery, which generates heat to be turned into electricity. It also has a laser which can burn holes in rocks from up to 7 meters away, in case of attack to analyse the chemical composition of the planet, and sensors which detect visible light, x-rays, neutrons and ultraviolet radiation, all for science. In essence, NASA has landed a nuclear power, laser-armed SUV on Mars for one fifth the cost of the Olympics. Oh, and it tweets.


The Mars rover family. Pictured, clockwise from bottom left: models of Sojourner, Spirit/Opportunity, two human males, and Curiosity. Photograph: NASA

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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Why have men become so lonely – and how does it affect their health?

New findings show the consequences of having a lonely heart.

Go out and get some friends. No, seriously. Hop on the Tube and act faux-interested in the crap-looking book your fellow commuter is reading, even if it's on their Kindle. Chances are it's better than the one in your bag, and they're probably a decent human being and just as lonely, like you and me.

A new slate of facts and figures are showing just how widespread loneliness, is while simultaneously being amazingly terrible for your health.

Research led by Steven Cole from the medicine department at University of California, Los Angeles is showing the cellular mechanisms behind the long known pitfalls of loneliness. Perceived social isolation (PSI) – the scientific term for loneliness –increases the exposure to chronic diseases and even mortality for individuals across the world.

The authors examined the effects of loneliness on leukocytes, also known as white blood cells, which are produced from stem cells in the bone marrow and are critical to the immune system and defending the body against bacteria and viruses. The results showed loneliness increases signalling in the sympathetic nervous system, which is responsible for controlling our fight-or-flight responses, and also affects the production of white blood cells.

Recently, the Movember Foundation, which focuses on men's health and wellbeing, carried out a survey with the help of YouGov investigating friendship and loneliness amongst men. The results are alarming, with only 11 per cent of single men across the spectrum in their early 20s to late-middle age saying they had a friend to turn to in a time of crisis, the number rising to 15 per cent for married men.

Friendship has shown not only to be important to a person's overall wellbeing, but can even add to a person's earnings. A previous study involving 10,000 US citizens over 35 years showed people earned 2 per cent more for each friend they had.

The Movember Foundation survey comes soon after the Office for National Statistics (ONS) showed that men in Britain make up 58 per cent of the 2.47m people living alone between the ages of 45 and 64. The reasons behind this figure include marrying later in life and failed marriages, which usually result in children living with the mother. Women still make up the majority of the 7.7m single-occupant households across all ages in the country, at approximately 54 per cent.

Chronic loneliness seems to have slowly become a persistent problem for the country despite our hyper-connected world. It's an issue that has made even Jeremy Hunt say sensible things, such as "the busy, atomised lives we increasingly lead mean that too often we have become so distant from blood relatives" about this hidden crisis. He's previously called for British families to adopt the approach of many Asian families of having grandparents live under the same roof as children and grandchildren, and view care homes as a last, not first, option.

The number of single-person households has continued to increase over the years. While studies such as this add to the list of reasons why being alone is terrible for you, researchers are stumped as to how we can tackle this major social issue. Here's my suggestion: turn off whatever screen you're reading this from and strike up a conversation with someone who looks approachable. They could end up becoming your new best friend.