Comet 67P/Churyumov-Gerasimenko by Rosetta’s OSIRIS narrow-angle camera. Image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Show Hide image

Rosetta becomes the first spacecraft to ever go into orbit around a comet

After a ten year chase, Rosetta became the first ever spacecraft to intercept and go into orbit around a comet - and over the next 18 months will begin searching for clues left over from the earliest moments of our Solar System.

Yesterday, after ten years of chasing, the European Space Agency’s (ESA) Rosetta spacecraft became the first ever to intercept and go into orbit around a comet. Now scientists can begin the next step in one of the most exciting investigations into how the Solar System formed that we’ve seen so far.

ESA scientists brought Rosetta to within 100km of the comet – a 3km by 5km rock called 67P Churyumov-Gerasimenko – and established a stable orbit by slowing it down with its thrusters. Perhaps surprisingly, while it’s taken ten years to get there, 67P was only discovered 50 years ago, but while not as famous a comet as Halley it’s just as scientifically interesting. Comets are considered to be primitive building blocks of the Solar System, and relics of the formation of the planets, while some even believe that they provided Earth with both water and other key ingredients too which were necessary for igniting the evolution of life. 

67P was first discovered in 1969 by Soviet astronomers Ivanovych Churyumov and Svetlana Ivanova Gerasimenko. The hope is that Rosetta will unlock the secrets of this early history – which is why it was named after the Rosetta Stone, the discovery of which in 1799 provided the key to translating Ancient Egyptian hieroglyphs and Demotic script into Ancient Greek (and thus any other language). It was launched from Europe’s spaceport in Kourou, French Guiana, in March 2004, into a long journey of loops around the Sun as it aimed to get onto the same trajectory as 67P.

Rosetta has trekked over 6bn km, passing by Earth three times, Mars once, and soaring past two asteroids, using the gravitational pull of those objects to change velocity and catch up with 67P. The riskiest part of this was when it was put into hibernation mode for 31 months to conserve power as its orbit brought it out to a distance roughly equal to the orbit of Jupiter and then back in again – where it was successfully awakened in January of this year, for the final part of the voyage.

Since May, Rosetta has performed a series of ten rendezvous manoeuvres to gradually fine-tune the spacecraft’s speed and trajectory to match those of the comet, which travels through space at speeds of up to 135,000km/h. Despite the unprecedented complexity of the mission, Rosetta’s smooth arrival was confirmed yesterday morning.

Here’s a video from the ESA showing Rosetta’s near-decade-long journey, and here’s how it’s going to orbit around 67P closer and closer:

The spacecraft now has quite the adventure to come, edging closer to the comet over the next six weeks in two triangular-shaped trajectories, first from a distance of 100km and then at 50km. Depending on the activity of the comet, it will further attempt a near-circular orbit from a distance of 30km, simultaneously scrutinising the comet’s surface for a suitable landing site for its small lander probe - Philae, named after an obelisk that was also used to decipher Egyptian hieroglyphs in the 19th century.

Philae will, sometime in November, detach from the main body of the spacecraft and anchor itself to the surface of the comet with a high-powered harpoon. Meanwhile, Rosetta will spend the next 18 months analysing the comet from every angle, retrieving crucial data enabling scientists to investigate how planets were created. The spacecraft will also accompany the comet around the Sun as it moves back out towards the orbit of Jupiter.

The mission has some similarities with Japan’s 2005 Hayabusa mission, which rendezvoused with and landed on an asteroid named Itokawa. It was meant to scoop up material from the asteroid’s surface, and return it to Earth for study – those samples arrived in 2010, but we know that its capture mechanism malfunctioned. To this day, there is some uncertainty as to whether the capsule managed to successfully collect the asteroid rock fragments.

The Rosetta mission is significantly more complex, too – while both Itokawa and 67P have miniscule gravitational pull, the former’s orbit around the Sun is relatively simple, and Hayabusa simply chased Itokawa closely around the Sun in the same orbit. Rosetta will, by reducing its speed to less than a metre per second, genuinely orbit 67P. As the comet moves towards the Sun and heats up, there are also likely to be gas and dust particles shed off into space to form its tail – and initial photographs sent to us by Rosetta, the clearest ever of a comet, do show some emissions already.

Yesterday, the elated ESA science and mission control experts celebrated the long awaited arrival, jokingly describing it as being similar to arriving at “Scientific Disneyland”. The arrival was streamed live on the ESA’s website, and Rosetta is already sending back incredible high-resolution images of the surface of 67P. So far, it looks a lot rockier and more solid than expected – less like a “dirty snowball”, and more like an asteroid.

Around the internet, there was excitement at the arrival of Rosetta. The hashtag #RosettaAreWeThereYet flooded Twitter, as people from all over the world eagerly awaited the news, like impatient school kids – even the Philae lander’s own Twitter account got involved:

But it didn’t stop there - after Rosetta finally reached its destination, even former Star Trek captain William Shatner joined the fun by engaging in playful chitchat, checking on operations with the Nasa and ESA Twitter account.

Although we know what the comet looks like from the outside, we don’t know what it looks like from the inside, and that’s what Rosetta and Philae will be uncovering over the next few months - as long as they have enough power from the craft’s huge solar panels, that is, as unlike most probes that venture out past the orbit of Mars, it has no onboard nuclear generator.

As one mission controller explained, Rosetta is going to finally “unlock the treasure chest of our own history”.

Artie Limmer/Texas Tech University
Show Hide image

Meet the evangelical Christian persuading believers that climate change is real

Katharine Hayhoe's Canadian missionary parents told her science and God were compatible. Then she moved to Texas. 

During Donald Trump’s presidential campaign, alarm rose with each mention of climate change. Denial, dismissal and repeated chants of “hoax” left no doubt as to his position.

Now President Trump’s withdrawal from the Paris Agreement has been seen as a seminal moment in the fight against climate change - one which many fear could lose the battle ahead of humanity.

But one scientist has been fighting a war of her own on the ground, against those who typically doubt the facts about global warming more than most - the evangelical Christian population of America.

And to make matters even more unusual, Katharine Hayhoe herself is an evangelical Christian who lives in the indisputably "bible belt" of Lubbock, Texas.

The atmospheric scientist has been named one of Time magazine's 100 most influential people and one of Politico’s 50 thinkers transforming American politics. Now she is using her considerable heft to speak to those who are hardest to convince that there is a manmade problem that threatens the Earth’s future.

I meet her at the science and music festival Starmus in Trondheim, Norway, where she is to address the attendees on Thursday in a talk entitled "Climate Change: Facts and Fictions".

Hayhoe was born in Canada, to missionary parents. Her father, a former science educator, showed her that there was no conflict between the ideas of God and science. However, it was something of a surprise to her when she discovered her pastor husband, whom she married in 2000, did not feel the same about climate change. It took her two years to convince him.

What started as a conversation became an organised project when she moved to America's South in the mid 2000s. 

“Moving to Lubbock was a culture shock," she tells me. "When I moved there I wasn’t doing much outreach, but it moved me in that direction.

“Lubbock is very conservative. It’s small and isolated.

“I would say the majority of people in Lubbock are either dismissive or doubtful about climate change. I was surrounded by people - neighbours, parents of friends, people at church, colleagues down the hall in the university - who weren’t convinced.”

So Hayhoe, who works as an associate professor and director of the Climate Science Centre at Texas Tech University, set to work. She began to collect the responses she was seeing to the climate change discussion and prepare her counter-argument.

“When I talk to people who are doubtful, I try to connect with the values they already have," she says. “The greatest myth is the myth of complacency - that ‘it doesn’t really matter to me’.

"But I would say that the second most insidious myth is that you only care about this issue if you’re a certain type of person. If you’re a green person, or a liberal person, or a granola person."

The stereotypes mean that people outside that demographic feel "I can't be that kind of person because that's not who I am", as she puts it.

Hayhoe convinced her husband using data, but rather than repeating a formula, she tries to find out what will resonate with different people: "For many groups, faith is a core value that people share.”

Whether she’s speaking to city planners, water company managers, school kids or Bible believers, Hayhoe says her hook is not the facts, but the feelings.

“I recently talked to arborists," she says. "For them, trees and plants are important, so I connect with them on that, and say ‘because we care about trees, or because we care about water or what the Bible says then let me share with you from the heart why I can about these issues because it affects something that you already care about’.

“My angle is to show people that they don’t need to be a different person at all - exactly who they already are is the kind of person who can care about climate change.”

Hayhoe came to public attention in the United States after appearing in a Showtime series on climate change. She has appeared on panels with Barack Obama and Leonardo DiCaprio, and launched a web series. As well as plaudits, this level of fame has also earned her daily threats and online abuse. 

“My critics think they’re coming from a position of religion, but they aren’t," she says. "They’re actually coming from a very specific political ideology which believes that the government should not have control over people’s lives in any way shape or form - very libertarian, free market, free economy, Tea Party."

She believes that in the United States, faith and politics has been conflated to the point "people can no longer tell the difference". 

“Now it’s conservatism that informs religion," she elaborates. "If the two are in conflict - like the Bible says God has given us responsibility over everything on this earth - then people say ‘oh, we can’t affect something as big as this Earth, God will take care of it anyway’."

Around half of those who attack her on social media identify themselves as Christians, she notes, but almost all call themselves conservatives. 

As a scientist, she’s been preparing data herself - naturally - on her online attackers, with depressingly familiar results.

“As soon as you stick your head out of the trench, you get it. There have been papers published showing that white men disproportionately form up that small group of dismissives. They’re almost all men. When I track my social media comments, I would say that 99.5 per cent of them are white men.

“Out of 1,000 negative comments, I have maybe five from women.”

After the climate change argument moved up a gear - following the Paris withdrawal - Hayhoe admits that she and her fellow scientists are concerned, although she pays tribute to the businesses, cities and states from the US that have committed to following the Paris agreement themselves.

On the subject of the chief white male denier, Trump himself, Hayhoe says she has a discussion point which she feels may convince him to think carefully about his role in the fight against global warming’s impact on humanity.

“I would attempt to connect with the values that he has and show him how acting on this would be in his best interests," she says.

“One guess would be ‘what do you want your legacy to be? What do you want to be known as, the man who destroyed the world, or the man who saved it?’”

Katharine Hayhoe is speaking at Starmus on Thursday June 22. For more details, visit Starmus.

Kirstie McCrum is a freelance journalist. Follow her @kirstiemccrum.

0800 7318496