Will you be able to see the transit?

Telescopes around the world — and in space — will be aimed at the Sun today to catch the rare astronomical event of a transit of Venus. Our planetary neighbour crosses in front of the Sun (from the viewpoint of Earth, that is) only twice every 120 years or so.  The last time this happened was in 2004; it won’t happen again until 2117.

This has professional and amateur astronomers alike jumping up and down with excitement, getting out their welding goggles and pinhole cameras to watch the event from their back yards. For tips on when and how you might be able to spot the transit, see TransitofVenus.org.

If you are trapped beneath clouds or in a part of the world that won’t be able to see it, there are live webcam streams being hosted by NASA starting at about 2:45 p.m. Pacific time (5:45 Eastern time), and by the Slooh telescope network, with ‘pre-game’ commentary starting at 2:30 p.m. Pacific time (5:30 p.m. Eastern time). The entire transit will take about seven hours.

Although much of the excitement around this transit is aimed at public-outreach efforts aiming to get the public interested in astronomy, there is also some real science to be done. Astronomer and transit enthusiast Jay Pasachoff of Williams College in Williamstown, Massachusetts, wrote in Nature a few weeks ago about the science goals. These include trying to ‘ground truth’ detections of exoplanets circling far-off stars, and getting a once-in-a-lifetime measure of the climate of Venus. Although there’s a probe in orbit around Venus, this gets a very limited view of the planet’s climate: it can basically see the atmosphere in only one spot at a time, making it impossible to know whether the changes it sees are due to changes in space or changes in time. A simultaneous measure of the climate along an entire pole-to-pole line is measurable only today.

Check back here for updates.

UPDATE 1 (4:30pm Pacific time)

Venus approaches the Sun from on the upper left hand side{credit}NASA SDO{/credit}

As predicted, Venus started its path across the Sun at around 3 p.m. Pacific time. Some fantastic photos have been released already, including this spectacular one from the space-bound Solar Dynamic Observatory (SDO) of Venus approaching the Sun.

SDO’s observations are going to be used to calibrate a couple of instruments on the observatory, including confirming where exactly the ‘north pole’ of the Sun lies in its view, and measuring the ‘point spread function’ of its telescope — how much light leaks from one pixel into others around it. SDO should also be able to take its own measure of how much oxygen is in Venus’s atmosphere.

The weather is looking perfect for observations from Hawaii — one of the best spots for viewing this transit and the source of NASA’s main webcast.

UPDATE 2: 6 June

Hawaii didn’t just have clear skies for the transit — it had the perfect conditions, known as ‘coronal skies’. “I held my thumb up to block out the Sun, in the traditional test carried out by solar astronomers, and the sky was the same blue right up to the edge of my finger.  That shows how low the scattering in the sky was,” says Pasachoff. It was, however, very windy, he adds, so they took short exposures to lock in details before pictures were blurred by motion, and they will have a lot of post-processing to do.

A photo snapped from the International Space Station{credit}Don Pettit / NASA{/credit}

Positive reports of good measurements have already come in from Arizona, Udaipur, Japan and, for the last half of the transit, from Australia.  The site in the Marquesas in the South Seas had instrument problems, says Pasachoff. He has had no report yet from New Mexico, where astronomers were using a new carbon dioxide filter to study Venus’s atmosphere.

Perhaps one of the most novel observations comes from the International Space Station, where astronaut Don Pettit snapped a photo of the transit from the window (see picture).

The Hubble space telescope, which, like our own eyes was too sensitive to be pointed directly at the Sun, was aiming to gather information about Venus from the sunlight reflected from Tycho crater on the Moon. Likewise, the European Space Agency’s Very Large Telescope in Chile was aimed at the Moon to catch these reflections. There are no reports from either as yet. David Ehrenreich of French National Centre for Scientific Research in Grenoble says that they will get the Hubble data by the end of the week, though analysis will take months.

All in all, “we had a wonderful day, even better than expected or hoped for,” says Pasachoff. “At this point, it is not possible to say if anything surprising turned up.”

“We are exhausted after spending almost seven hours outside, but we feel great, and we can’t wait to look at our observations in detail.”

The Dragon capsule splashed down to a successful landing in the Pacific Ocean just before noon Eastern time today, completing an up-and-down journey to the International Space Station. While this was done many times with the US space shuttle — and is still being done with Russian Soyuz capsules — the success of Dragon is significant because it is the first private, commercially owned vehicle to make that trip. The capsule, built by SpaceX, was launched on one of the company’s Falcon 9 rockets on 22 May, and docked with the space station last week.

SpaceX should begin in earnest now on 12 station resupply missions under terms of a $1.6 billion commercial cargo contract with NASA. The company has plans to certify the capsule for use by astronauts in the next several years.

At over $100 million per launch, Dragon is still not a cheap ride to the station. But it is a bargain basement price compared to the space shuttle, which according to a life-time analysis cost a whopping $1.5 billion per launch. The key difference is the way the rides are bought. The United States “owned” the space shuttle, but paid through the nose for commercial contractors such as Boeing to build it — under a procurement strategy called “cost-plus” that offered few incentives for contractors to find efficiencies.  SpaceX and other upstart companies want to sell rides into space not just to NASA but to anyone that wants one — and they want to sell those rides as the commercial airline industry does.

Image credit: Michael Altenhofen

After 35 years, astronomer Jill Tarter (pictured) is retiring from the Search for Extraterrestrial Intelligence (SETI) — a field she helped to pioneer and popularize, most recently at the SETI Institute in Mountain View, California. Tarter, who inspired the late Carl Sagan to create Ellie Arroway, the fictional heroine of the novel and movie Contact, says that she will instead focus her efforts on what she calls “the search for intelligent funding”.

“Last year’s hibernation was a real wake-up call,” she explains, referring to the seven-month shutdown of the institute’s Allen Telescope Array in northern California, triggered when its partners at the University of California, Berkeley, withdrew from the project (see Nature 475, 442–444; 2011). The array was reopened in December after the institute put together a ‘crowdsourcing’ website, SETIStars, and raised more than US$200,000 from individual donors. But that was a best a stopgap, says Tarter: “If we don’t get funding under control,” she says, “we’ll be a SETI Institute that doesn’t do SETI.”

The institute’s research programme costs about $3 million a year, says Tarter. “So our first priority is to establish an endowment that can provide that kind of funding today, tomorrow and a century from now.” (Federal funding has been out of the question since 1993, when Congress slashed SETI from the NASA budget with extreme prejudice; politicians simply cannot resist the temptation to ridicule the search as a quest for ‘little green men.’) Using the standard 5% rule-of-thumb for interest, that means raising at least $60 million. “But what’s interesting to me,” says Tarter, “is that, at any given time, there are more than a hundred campaigns underway in the United States to raise that much for a lab building, or a concert hall. So it’s clearly not an impossible amount to raise.”

It’s not a job for amateurs, though: Tarter plans to assemble a group of experienced fund-raisers for her campaign — “people with the equivalent of large Rolodexes,” she says, “who figure that SETI is too important to fail.”

Fortunately, adds Tarter, when her hoped-for donors ask what their money is buying, she will be able to point to a substantial upgrade in the Allen Array’s search capabilities being spearheaded by Gerald Harp, her successor as head of the SETI Institute’s search programme. In the months since the restart, that programme has mostly been listening for artificial signals in the same patch of sky being scanned by NASA’s Kepler satellite, which has already found more than 60 confirmed planets there, plus thousands more candidate planets. Right now, the array can listen to only three stars at once. But this summer, Harp is planning to test a signal-analysis method that would allow it to do simultaneous, low-resolution scans of many more stars — which means that the array could efficiently carry out targeted searches and wide-field surveys at the same time.

“We always reserve the right to get smarter, and do new things,” notes Tarter, who will be feted in June at the SETI Institute’s SETIcon II festival.

Image courtesy of Seth Shostak

The first stage of a European mission to Mars is still limping towards a 2016 launch, even though the European Space Agency (ESA) has not yet raised full funding for the mission, Jean-Jacques Dordain, ESA’s director general, told Nature today at a global space-exploration conference.

The suite of Mars missions — which is to include an orbiter as well as landed elements following launches in 2016 and 2018 — was originally a joint plan with NASA. In that formulation, a rover, launched in 2018, would have marked the beginning of a Mars sample-return mission architecture.

But NASA pulled out after the administration of US President Barack Obama deemed the plan too costly a commitment. Picking up the pieces after the divorce, Dordain was able to keep the mission alive in part by bringing Russia into the fold. Russia will contribute Proton rockets for the launches in 2016 and 2018. But Dordain says he is still €350 million (US$440 million) short of the estimated €1.2-billion cost of the mission.

He is trying to raise those funds in multiple ways, including asking existing member states to pay more, and also through the recruitment of new ESA member-states. Although he is not yet confident enough to say the mission will go ahead, he also is unwilling to give up. He hopes to have more funding commitments lined up before an ESA meeting next month.  “I cannot in three months re-plan everything we had built up in three years with NASA,” he says. “I need time.”

Image credit: ESA

It was a rare confluence — the heads of the space agencies for Europe, Canada and Russia, along with senior representatives from the space agencies of India and Japan — all up on the dais together at a hotel in Washington DC, where they were on hand on 22 May to talk about the benefits of international collaboration at the Global Space Exploration Conference.

Interestingly, the leader of the space agency whose headquarters is just a few blocks away was not on the stage. That’s because NASA administrator Charles Bolden was in Florida, watching the attempt by SpaceX to send its Dragon capsule to the International Space Station.

But perhaps it was somewhat appropriate for NASA to be absent. Increasingly, the agency has had a hard time consummating its joint ventures, and Europe in particular has had to turn elsewhere for partners.

NASA has also shifted its exploration goals relative to other nations. While NASA now intends to pursue manned missions to asteroids, representatives of several other space agencies reiterated that the Moon was still squarely in their sights.

Vladimir Popovkin, the head of Roscosmos, the Russian space agency, said that Russia will pursue extensive, long-lived operations at the Moon’s surface. “We’re not talking about repeating what mankind achieved 40 years ago,” Popovkin said, through a translator.  “We’re talking about establishing permanent bases.” Similarly, JAXA, the Japanese Space Agency, issued a clear pronouncement about targeting the Moon.  “We are looking at the Moon as our next target for human exploration,” said Yuichi Yamaura, an associate executive director at JAXA.

China was another conspicuously absent member of the aerospace club as represented on stage. Those present were asked whether they should be doing more to collaborate with China.  “We’re all for it,” says Popovkin. “We have to talk to China.” Steve MacLean, the president of the Canadian Space Agency, described how impressed he was by China’s space operations after a recent visit. He says it would be “prudent” to explore more collaboration.