Good news: Engineers have resumed vibration testing of the James Webb Space Telescope after pinpointing and fixing the unexpected movement in one of the restraint mechanisms that hold the telescope’s folded mirrors in place during launch.
Overall, it increasingly looks like Webb is going to get off the ground as presently scheduled, in October 2018.
The European Southern Observatory (ESO) today signed contracts for the construction of the mirrors and sensor for its Extremely Large Telescope (ELT).
At a ceremony today at ESO’s Headquarters four contracts were signed for major components of the Extremely Large Telescope (ELT) that ESO is building. These were for: the casting of the telescope’s giant secondary and tertiary mirrors, awarded to SCHOTT; the supply of mirror cells to support these two mirrors, awarded to the SENER Group; and the supply of the edge sensors that form a vital part of the ELT’s huge segmented primary mirror control system, awarded to the FAMES consortium. The secondary mirror will be largest ever employed on a telescope and the largest convex mirror ever produced.
The construction of the 39-metre ELT, the largest optical/near-infrared telescope in the world, is moving forward. The giant telescope employs a complex five-mirror optical system that has never been used before and requires optical and mechanical elements that stretch modern technology to its limits.
Meanwhile it remains unclear when and where the Thirty Meter Telescope (TMT) will be built.
The privately funded Breakthrough Initiatives project has committed funds to upgrade the Very Large Telescope in Chile in exchange for telescope time to look for Earthlike planets in orbit around Alpha Centauri.
Facebook’s Mark Zuckerberg, Russian entrepreneur Yuri Milner and physicist Stephen Hawking are hoping to find Earth-like planets in our neighbouring star system, Alpha Centauri. Together they will upgrade the Very Large Telescope (VLT) to look for potentially habitable worlds as part of the ‘Breakthrough’ initiatives.
These planets could be the targets for a launch of tiny space probes to track down aliens within our lifetimes, the European Southern Observatory (ESO) said.
This is exactly how astronomy used to function. Rather than get money from the government in exchange for doing the research it wanted done, astronomers obtained funds from wealthy individuals or businesses to build and upgrade their telescopes in exchange for doing the research that interested these funding sources. The difference? The work was privately funded voluntarily, rather than coerced from the public through taxes.
Back in 2012 the National Science Foundation (NSF) proposed that it cease funding a slew of older, smaller telescopes in order to use that money to fund the construction and operation of newer more advanced facilities. This article, focused on the fate of the Arecibo Observatory in Puerto Rico, provides a nice table that shows the status of these telescopes.
The options were either to find new funding, be mothballed, or even demolished. It appears that most of the telescopes in question have found new funding and will remain in use in some manner. The one telescope that has apparently failed to obtain any additional funding from others is the McMath–Pierce Solar Telescope on Kitt Peak in Arizona, which when built in 1962 was the world’s largest solar telescope, an honor for which it is still tied.
In 2015 I had written an article for Sky & Telescope about how these budget cuts were effecting the telescopes on Kitt Peak. At that time the people in charge of McMath-Pierce were hunting for new support but were coming up short. Almost two years later it appears that their hunt has been a failure, and the telescope will likely be shut down, and possibly demolished.
It will be a sad thing if McMath-Pierce is lost, but I am not arguing to save it. If its observational capabilities were truly valuable and needed by the scientific community than someone would have come forward to finance it. That no one has suggests that the money really can be spent more usefully in other ways.
A new theory has been proposed by astronomers to explain the unprecedented dimming of Tabby’s Star, and it isn’t an alien civilization.
If Tabby’s star devoured a planet in the past, the planet’s energy would have made the star temporarily brighten, then gradually dim to its original state. The bigger the planet was, the longer the star would take to dim. Depending on the size of the planet, this event could have happened anywhere between 200 and 10,000 years ago.
As the planet fell into its star, it could have been ripped apart or had its moons stripped away, leaving clouds of debris orbiting the star in eccentric orbits. Every time the debris passes between us and the star, it would block some light, making the star seem to blink.
If true, this theory would suggest that such events can happen more than scientists has expected. Moreover, this theory can be tested during future observations when the star experiences its next dimming.
Using the Hubble Space Telescope astronomers have taken a peek at the interstellar material that the two Voyager spacecraft will travel through as they move out and leave the solar system in the coming decades.
Voyager 1 is 13 billion miles from Earth, making it the farthest human-made object ever built. In about 40,000 years, after the spacecraft will no longer be operational and will not be able to gather new data, it will pass within 1.6 light-years of the star Gliese 445, in the constellation Camelopardalis. Its twin, Voyager 2, is 10.5 billion miles from Earth, and will pass 1.7 light-years from the star Ross 248 in about 40,000 years.
For the next 10 years, the Voyagers will be making measurements of interstellar material, magnetic fields, and cosmic rays along their trajectories. Hubble complements the Voyagers’ observations by gazing at two sight lines along each spacecraft’s path to map interstellar structure along their star-bound routes. Each sight line stretches several light-years to nearby stars. Sampling the light from those stars, Hubble’s Space Telescope Imaging Spectrograph measured how interstellar material absorbed some of the starlight, leaving telltale spectral fingerprints.
Hubble found that Voyager 2 will move out of the interstellar cloud that surrounds the solar system in a couple thousand years. The astronomers, based on Hubble data, predict that the spacecraft will spend 90,000 years in a second cloud before passing into a third interstellar cloud.
This is very clever science. It allows data from Hubble to complement the data from the two Voyager spacecraft to better understand the interstellar regions that surround our solar system.
Astronomers are predicting that a two binary stars that orbit so close together that they share an atmosphere will merge and explode as a bright red nova in approximately five years.
According to the actual paper [pdf], they also predict that this will be a naked eye event, visible in the northern hemisphere.
Note that a red nova is not a supernova. These are different types of explosions, with the supernova many times more powerful and rare. Nonetheless, the event itself will spectacular, should the prediction be correct.
For the first time astronomers have pinned down the location of a fast radio burst (FRBs), short bursts lasting only seconds that were only discovered about a decade ago.
A dim dwarf galaxy 2.5 billion light years from Earth is sending out the mysterious millisecond-long blasts of radio waves, researchers report Wednesday in Nature and Astrophysical Journal Letters. The bursts traverse vast expanses of time and intergalactic space before reaching our planet. “This really is the first ironclad association of a fast radio burst with another astronomical source, so it’s a pretty huge result,” said Duncan Lorimer, an astronomer at West Virginia University who reported the first detection of a fast radio burst (FRB) in 2007.
The uncertainty of science: Only 18 FRBs have been identified since they were first discovered. Until now, it was unclear whether they occurred in our galaxy or beyond, though it was suspected they were coming from other galaxies. This discovery proves that. What remains unknown is what causes the burst, which signals an energy pulse equivalent to that of 500 million suns.
“I am not exaggerating when I say there are more models for what FRBs could be than there are FRBs,” said Cornell astronomer Shami Chatterjee, the lead author of the new Nature paper. Many scientists think the bursts are emitted by distant neutron stars, the super-dense embers of exploded suns. But some believe they must originate in our own galaxy. Still more suggest that FRBs could be caused by cataclysms like a supernova or a collision of two stars. This last theory was compelling because most FRB detections were one-off events — astronomers never spotted more than one flare from a single source.
Today’s announcement was made possible by the fact that the burst itself is repeating. In fact, it is the only FRB so far known to do so, which also means that what they learn about it might not be applicable to the other bursts.
Vera Rubin, whose work helped confirm the existence of dark matter, passed away December 25 at the age of 88.
In the 1960s, Rubin’s interest in how stars orbit their galactic centers led her and colleague Kent Ford to study the Andromeda galaxy, M31, a nearby spiral. The two scientists wanted to determine the distribution of mass in M31 by looking at the orbital speeds of stars and gas at varying distances from the galactic center. They expected the speeds to conform to Newtonian gravitational theory, whereby an object farther from its central mass orbits slower than those closer in. To their surprise, the scientists found that stars far from the center traveled as fast as those near the center.
After observing dozens more galaxies by the 1970s, Rubin and colleagues found that something other than the visible mass was responsible for the stars’ motions. Each spiral galaxy is embedded in a “halo” of dark matter—material that does not emit light and extends beyond the optical galaxy. They found it contains 5 to 10 times as much mass as the luminous galaxy. As a result of Rubin’s groundbreaking work, it has become apparent that more than 90% of the universe is composed of this invisible material. The first inkling that dark matter existed came in 1933 when Swiss astrophysicist Fritz Zwicky of Caltech proposed it. But it was not until Rubin’s work that dark matter was confirmed.
Rubin was a top notch astronomer, which is why she was part of this important discovery. She was also an exception, as at the time relatively few women were interested in becoming astronomers. Be prepared, however, for a slew of articles in the next few days focused not about her work and her contributions to science, but focused instead almost entirely on the sexist oppression she had to overcome in the evil sexist male chauvinist society of mid-twentieth-century America.
All those articles will be wrong. While there were certainly obstacles in Rubin’s way because of her sex, they were hardly as bad as it will be made out to be. Worse, this focus on gender and oppression will distract from honoring the passing of a great astronomer. It will also distract from the significance of her discovery, which continues to baffle astronomers a half century later.
NASA now expects it will take a month to assess and fix the issues uncovered during vibration testing of the James Webb Space Telescope.
Thomas Zurbuchen, the new head of NASA’s Science Mission Directorate (SMD), told SpacePolicyOnline.com that dealing with the problem likely will consume one of the remaining six months of schedule reserve.
No one at NASA has as yet explained exactly what the “anomalous readings” were during vibration testing. Nor did Zurbuchen indicate what the fix would be.
A computer analysis of the light fluctuations of Tabby’s Star suggest to astronomers that the changes are not caused by objects blocking the star (such as an alien Dyson Sphere under construction) but are instead natural variations caused as the star evolves.
This conclusion is decidedly uncertain. They do not know the nature of this stellar evolution. And they are applying avalanche models to the star to come to this conclusion.
Because the red giant star Betelgeuse rotates far faster than it should, astronomers are now theorizing that when it expanded into its present red giant phase about 100,000 years ago it swallowed a companion star which contributed its own angular momentum to the system to speed up the rotation.
This theory is bolstered by evidence of a shell of matter surrounding Betelgeuse that is possibly a remnant of that destroyed star.
