Euclid releases new images and first science results

Euclid image
Click for original image.

The Euclid science team today released five early science images in connection of the publication of ten papers.

The picture to the right is one of those images, cropped, reduced, and sharpened to post here. From the caption:

In this image Euclid showcases NGC 6744, an archetype of the kind of galaxy currently forming most of the stars in the local Universe. Euclid’s large field-of-view covers the entire galaxy, capturing not only spiral structure on larger scales but also exquisite detail on small spatial scales. This includes feather-like lanes of dust emerging as ‘spurs’ from the spiral arms, shown here with incredible clarity.

Scientists are using this dataset to understand how dust and gas are linked to star formation; map how different star populations are distributed throughout galaxies and where stars are currently forming; and unravel the physics behind the structure of spiral galaxies, something that is still not fully understood after decades of study.

Euclid is a wide-field space telescope that has instruments that observe in both visible and near-infrared wavelengths. Its primary mirror at 1.2 meters is half the width of Hubble’s. More details about these early images and links to the new science results can be found here.

Unlike Hubble, it appears Euclid will not be used as a general observatory, at least initially. Its primary goal is to do a survey of one third of the sky, focusing on extragalactic sources outside the Milky Way. Once this is complete however it is possible the space telescope will be made available for other observations.

NASA instrument for European space telescope flawed and must be rebuilt

The NASA instrument for Europe’s Euclid optical/near-infrared space telescope has been found defective and must be rebuilt, thus delaying the launch of the telescope by at least one year.

What interested me about this telescope is its goals and specifications:

Euclid is a two-ton space telescope selected by ESA in 2011 as a medium-class mission in its Cosmic Vision program of space science missions. The spacecraft features a 1.2-meter telescope with visible and near-infrared instruments to study dark energy and dark matter, which combined account for about 95 percent of the universe. Euclid will operate at the Earth-sun L-2 Lagrange point, 1.5 million kilometers from Earth, that is used by other infrared astronomy missions.

With a mirror about half the size of Hubble’s, this telescope will act as a partial replacement and back up for it. In fact, it will likely make numerous ground-breaking discoveries, as every optical telescope placed above the atmosphere has so far done.

Meanwhile, the article provided no information on the flaws, who built the flawed instrument, and who will pay for the delays its failure will cause.

Astronomers propose giant super Hubble replacement

A major university consortium that manages many ground- and space-based telescopes has proposed that a new giant optical space telescope be built to replace Hubble.

A report published today by the Association of Universities for Research in Astronomy in Washington, D.C., lays out the rationale for another orbiting observatory. It will have a mirror as big as 12 meters across, to both look for habitable planets around other stars and peer deep into the early aeons of the universe.

Hubble has a mirror 2.4 meters across, so this would be significantly larger. In fact, if built this new space telescope would make it bigger than any ground-based telescope that exists today.

As the article notes, the cost over-runs and delays of the infrared James Webb Space Telescope — which went from a $1 billion budget to $8 billion — will likely make Congress reluctant to fund a new giant project like this. Nonetheless, this report gives us a hint of where the astronomy community wants to head in future decades. For the past two decades they have poo-pooed the construction of a new and larger optical space telescope. It appears from this report that this culture is now changing.

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.

New exoplanets make astronomers long for a telescope to see them

The plethora of new exoplanet discoveries has astronomers longing for a telescope that can see them up close.

Astronomers need either a giant space telescope equipped with a device for blocking starlight, or an interferometer, consisting of several telescopes flying in formation. NASA did develop a proposal for such a space telescope, called Terrestrial Planet Finder, and the European Space Agency hoped to fly a similar mission called Darwin. But budgetary constraints have left both missions in limbo, unlikely to advance to the front of either agency’s queue until well into the next decade. At the conference, Traub raised the issue. “People are not thinking deeply about the distant future. People are wrapped up with what they’re doing right now,” he says. “Clearly, I’m concerned.”

Are astronomers finally going to push for a replacement for Hubble?

Astronomers are considering the merger two space missions to create a new optical/ultraviolet space telescope. The mission would be designed to do both deep cosmology and exoplanet observations.

The two communities would both like to see a 4–8-metre telescope in space that would cost in excess of $5 billion. “Our interests are basically aligned,” says [Jim Kasting, a planetary scientist at Pennsylvania State University]. Such a mission would compete for top billing in the next decadal survey of astronomy by the US National Academy of Sciences, due in 2020.

This story is big news, as it indicates two things. First, the 2010 Decadal Survey, released in August 2010, is almost certainly a bust. The budget problems at NASA as well as a general lack of enthusiasm among astronomers and the public for its recommendations mean that the big space missions it proposed will almost certainly not be built.
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