Tag Archives: Gaia

An update on Gaia’s first year of astronomical observations

European scientists today released an update on the status and scientific observations of their space telescope Gaia, designed to survey the location and distance of a billion stars.

The press release provides a basic summary of the spacecraft’s condition, which appears good, as well as an overview of some of the most interesting observations, though with little detail. This is because the first scheduled release of Gaia hard data will not happen until a year from now, thus giving the scientists who run the project a year to analyze it and publish their own papers.

Loose fibers significantly cuts Gaia’s output

Europe’s Gaia telescope, designed to precisely measure the motions of a billion stars in the Milky Way, will have its accuracy cut in half because of the presence of loose fibers on the telescope’s sun shield that are allowing too much stray light in.

These fibres were spotted on Gaia before launch, but cutting them off was considered too risky, because that could allow small particles to enter the spacecraft. Another option, taping them down, was also ruled out because the increased stiffness could prevent the sunshield from unfolding.

The stray light shouldn’t affect measurements of the galaxy’s brightest stars, says Gaia science team member Anthony Brown at the Leiden Observatory in the Netherlands, but it will double the expected errors on most of the stars in the Milky Way, which are much fainter.

For astronomers this is a great tragedy. Gaia will still teach us much, just not as much as they had hoped.

Gaia commissioning complete

After several months of in-orbit analysis, engineers have declared the European space telescope Gaia ready to begin research.

There have been several issues that had raised concerns, but from the article it sounds as if the engineers have either corrected the problems or have found ways to overcome or mitigate them.

Gaia will measure the movement and location of a billion stars, allowing astronomers to map the Milky Way better than ever before.

Problems with the European Gaia space telescope

Shades of Hubble: The first data from Europe’s Gaia space telescope, launched to map a billion Milky Way stars, will be delayed 9 months while engineers grapple with several problems.

Gaia managers started taking test images early this year, but soon noticed three issues. For one, more light than anticipated is bending around the 10-metre sunshield and entering the telescope.

Small amounts of water trapped in the spacecraft before launch are being released now that the telescope is in the vacuum of space, and more ice than calculated is accumulating on the telescope’s mirrors. In addition, the telescope itself is expanding and contracting by a few dozen nanometres more than expected because of thermal variations.

Mission managers say the number of stars detected will remain the same even if these complications remain untreated, but the accuracy in measurements of the fainter stars will suffer.

Unlike Hubble, however, there is no way to send a shuttle and a team of astronauts to Gaia to fix it. And it sounds like these issues will have an impact on the telescope’s abilities to gather its intended data.

This story raises my hackles for another reason. Gaia was a very technically challenging space telescope to build, but it was far easier and less cutting edge than the James Webb Space Telescope. It also cost far less. What will happen when Webb gets launched later this decade? How likely is it to have similar issues? Based on a story I just completed for Sky & Telescope on the difficulties of building ground-based telescopes, I’d say Webb is very likely to have similar problems, with no way to fix them. The American astronomy community could then be faced with the loss of two decades of research because they had put all the eggs into Webb’s basket, and thus had no money to build anything else.

“A lot of investment in green technology has been a giant scam, if well intentioned.”

“A lot of investment in green technology has been a giant scam, if well intentioned.”

The quote, and entire interview, are significant for two reasons. First, the interview is seeped with many skeptical opinions about human caused global warming, is very critical of that movement’s effort to politicize science, and the person being interviewed is James Lovelock, the founder of of the concept of Gaia, a former strong advocate of global warming but now a skeptic.

Most significant however is where the interview is published. It is in Nature, one of the most important and influential science journals, which previously has been aggressively pushing global warming politics for years. That they allowed these politically incorrect opinions within their walls and then broadcast them to their readers signals a major cultural shift within the science community. It is beginning to be acceptable to be a skeptic again!

Gaia, a astronomical space probe designed to pinpoint the location of a billion stars to map the Milky Way, was successfully launched today.

Gaia, a astronomical space probe designed to pinpoint the location of a billion stars to map the Milky Way, was successfully launched today.

This is an important spacecraft, but don’t expect to hear anything about its work now for a long time, as it will take a few years to accumulate the data involved and then a years beyond that to analyze it. Nonetheless, when Gaia’s work is finished we will have our first reasonably good map of the Milky Way, with the ability to project that map forward and backward in time.

The global warming advocate who invented the concept of “Gaia” now admits he was wrong about global warming.

The global warming advocate who invented the concept of “Gaia” now admits he was wrong about global warming.

“The problem is we don’t know what the climate is doing. We thought we knew 20 years ago. That led to some alarmist books – mine included – because it looked clear-cut, but it hasn’t happened,” Lovelock said. “The climate is doing its usual tricks. There’s nothing much really happening yet. We were supposed to be halfway toward a frying world now,” he said.

“The world has not warmed up very much since the millennium. Twelve years is a reasonable time… it (the temperature) has stayed almost constant, whereas it should have been rising — carbon dioxide is rising, no question about that,” he added.