Connect with us

Science

Celebrating 30 years of the Hubble Space Telescope | Space

Published

on

Celebrating 30 years of the Hubble Space Telescope | Space_5ea4bc398ac9f.jpeg

It’s been 30 years since NASA launched the Hubble Space Telescope on April 24, 1990. The observatory was carried aloft in the payload bay of space shuttle Discovery, and for three decades Hubble’s history was closely intertwined with the shuttle’s. The telescope was originally scheduled for launch in 1986, but the tragic Challenger accident at the start of that year led to a four-year delay.

When Hubble finally made it into orbit, it still wasn’t smooth sailing. Almost immediately, scientists discovered a serious flaw in the telescope’s mirror that made stars look slightly blurred, rather than like sharp pinpoints of light. Since the whole point of putting Hubble above the Earth’s atmosphere was to avoid the blurring that ground-based telescopes suffer from, this was disastrously bad news. 

For any other astronomical satellite the situation would have been mission-ending, but not for Hubble, which was designed all along to be serviceable in space — another way its destiny was inextricably tied to the shuttle.

Related: The Hubble Space Telescope and 30 years that transformed our view of the universe

The first servicing flight, by space shuttle Endeavour in December 1993, was originally planned as a routine maintenance visit. Instead it became an urgent rescue mission. In a series of tense spacewalks, the astronauts replaced Hubble’s main camera with a redesigned one and installed a corrective optics package for the other instruments. 

In what may be the second greatest feat of human spaceflight (after the moon landings), Hubble was brought back up to its design spec. Now it could see all the wonders of the universe with a clarity that could never be achieved from Earth’s surface. Four subsequent servicing missions, the last by space shuttle Atlantis in May 2009, have ensured Hubble remains the world’s most powerful telescope to this day.

As dark as the night sky looks from ground level, it never gets completely black due to airglow in the atmosphere, which limits the ability of earthbound astronomers to take long-exposure photographs. At Hubble’s high altitude, however, the background sky really is pitch black, which means it can see incredibly faint objects if it stares at the same patch of sky for long enough. That’s the rationale behind one of Hubble’s most impressive achievements: the series of ‘deep-field‘ images, of which the first was released in 1996 and the most recent — the Hubble Extreme Deep Field (HXDF) — in 2012.

“Before Hubble, we knew essentially nothing about galaxies in the first half of the life of the universe,” Garth Illingworth, one of the scientists behind the project, told All About Space. “That’s the first 7 billion years of the universe’s 13.8-billion-year life. Now Hubble, through remarkable surveys like HXDF, has probed into the era of the first galaxies.” 

Through this type of work, Hubble has discovered galaxies like GN-z11, the most distant discovered by Hubble. “Just 400 million years after the Big Bang, Hubble is looking back through 97% of all time to see GN-z11, far outstripping what can be done with the biggest telescopes on the ground.” 

Although Hubble is best known for the spectacular images taken with its cameras, these are complemented by other, equally important instruments in the form of spectrographs. The latter add a whole new dimension, Hubble’s senior project scientist Jennifer Wiseman said. “The spectrum taken with the STIS spectrograph on Hubble tells you about the composition of the gases and the material in the system, and the motions of the material as well. Having cameras and spectrographs gives you a very powerful combination of scientific tools.” 

Perhaps the most dramatic use of Hubble’s spectrographs — and one that few astronomers would have envisioned when it was launched 30 years ago — is in exploring the atmospheres of recently discovered exoplanets around distant stars. “This technique called transmission spectroscopy has been leveraged about 100 times,” Nikole Lewis, an exoplanet specialist at Cornell University, told All About Space. “We can actually look at starlight filtered through those planet atmospheres to find out something about what’s in the air around these planets beyond our solar system.” 

It’s particularly exciting to find traces of chemicals which, on Earth, we associate with life — water being the most obvious one. Hubble made headlines in 2019 with the first discovery of water in the atmosphere of an Earth-size exoplanet, K2-18b, which orbits in the habitable zone of a red dwarf star.

In its 30 years in space, the Hubble Space Telescope has contributed to every aspect of astronomy — from our own solar system to the most distant galaxies — and more than 15,000 scientific papers have been published detailing its results. These include many exciting new discoveries, including evidence of the supermassive black holes lurking in the centers of galaxies.

One Hubble scientist, Adam Riess of the Space Telescope Science Institute (STScI), which operates Hubble in partnership with NASA, was awarded a share of the 2011 Nobel Prize for his part in observations that the universe’s expansion is accelerating, suggesting the presence of mysterious dark energy.

NASA astronaut Kathy Thornton accesses Hubble repair equipment during the first servicing mission, in 1993.

NASA astronaut Kathy Thornton accesses Hubble repair equipment during the first servicing mission, in 1993. (Image credit: NASA)

As the senior project scientist for Hubble, it’s Jennifer Wiseman’s job to keep track of the full range of Hubble’s scientific activities in different areas of astronomy. “Thirty years into the mission, the scientific productivity of Hubble is at an all-time high,” she told All About Space. “The reason is that the servicing missions, especially the final one in 2009, have been very successful, keeping Hubble very fit for great observations and cutting-edge science. Clever new observing techniques developed by Hubble scientists have boosted new discoveries as well. And the outstanding expert operations team on the ground — engineers, technicians, managers and computer support — keep diligent watch over Hubble’s subsystems to keep science return at a maximum as Hubble ages.”

So what’s the payoff for the scientific community? “Currently there are almost a thousand science papers published every year based on data from Hubble,” Wiseman said. “That’s more than ever before. About half of these are based on data taken from the Hubble archive. This is fantastic. It means that data originally taken for one scientific purpose is being used again for a different scientific purpose — a great return on investment!” 

Some of the scientists who work with Hubble today were still at school — or not even born — when it was launched 30 years ago, while others have been closely involved with it throughout that time. In the latter category is Colin Norman, a senior staff member at STScI who watched Hubble’s launch from Cape Canaveral, Florida, in April 1990. 

“Hubble has changed the landscape of astronomy and astrophysics,” he said. “It has far exceeded its early goals — no other science facility has ever made such a range of fundamental discoveries. It’s been a privilege to be associated with this effort that has become embedded in the culture of our time.” 

That last point is an interesting one. For all its groundbreaking scientific discoveries, Hubble’s most unique achievement is arguably the inspirational impact it’s had on the general public. It would be an understatement to say it’s the most famous telescope in history. 

Before Hubble, people without a special interest in astronomy probably couldn’t have named a single telescope. Yet today ‘Hubble’ is a household name, instantly recognizable to people all over the world and a symbol of both the brilliance of human ingenuity and the wonders of the universe.

What’s the reason for Hubble’s uniquely iconic status? “It reads like a movie script; it has a story arc,” Ray Villard, STScI’s news director, said. “The anticipation of launch, the optical failure, redemption with the servicing missions — then more drama when it was cancelled in the last decade.” 

Fortunately that cancellation was averted, and Hubble is still with us — hopefully for many years to come. As Villard says, “Well toward 2030 we’re back to doing some of the best science we think we can ever do with Hubble.” 

This article was adapted from a previous version published in All About Space Bookazine, a Future Ltd. publication. Follow us on Twitter @Spacedotcom and on Facebook.

Continue Reading
Click to comment

Leave a Reply

Your email address will not be published. Required fields are marked *

Science

Astronomers Detect a Suspiciously Shaped Galaxy Lurking in The Very Early Universe

Published

on

By

Astronomers Detect a Suspiciously Shaped Galaxy Lurking in The Very Early Universe_5ec5b2be6848e.jpeg

Around 13.8 billion years ago, somehow the Universe popped into existence. But it didn’t come fully equipped. At some point, the first stars formed, and the first galaxies. How and when this happened is still a mystery astronomers are trying to solve… but one galaxy could have a vitally important key.

 

It’s called DLA0817g – nicknamed the Wolfe Disk – a cool, rotating, gas-rich disc galaxy with a mass of about 72 billion times that of our Sun. And the Atacama Large Millimeter/submillimeter Array has snapped it a massive 12.5 billion light-years away – when the Universe was just 10 percent of its current age.

It’s the earliest rotating disc galaxy astronomers have found yet, and its very existence changes our understanding of galaxy formation in the early Universe.

Most of the galaxies in the early Universe are a hot mess, literally. They’re all blobby, with stars flying every which way, and rather high temperatures. Astronomers have interpreted this to mean that they grew large by colliding and merging with other galaxies – a hot, messy process.

“Most galaxies that we find early in the Universe look like train wrecks because they underwent consistent and often ‘violent’ merging,” explained astronomer Marcel Neeleman of the Max Planck Institute for Astronomy in Germany.

“These hot mergers make it difficult to form well-ordered, cold rotating disks like we observe in our present Universe.”

 

Under this scenario, it takes a long time for the galaxies to cool down and smooth out into the more orderly rotating disc galaxies like the Milky Way. We don’t generally start seeing them until about 4 to 6 billion years after the Big Bang.

This is the “hot” mode of galaxy formation. But astronomers had also predicted and simulated another way – the “cold” mode. 

First, you need to start with the primordial soup, an ionised quark-gluon plasma that filled the Universe before the formation of matter. To go from this homogeneous plasma to a Universe filled with stuff, astrophysicists have run simulations that suggest dark matter is responsible.

We don’t know what dark matter is. We can’t detect it directly, but it interacts gravitationally with normal matter. It helps to hold galaxies together, and we believe that it could be crucial to galaxy formation, clumps of it pulling together gas and stars into galaxies.

Supercomputer simulations have shown that a massive network of dark matter in the early Universe could have facilitated the formation of cool galaxies. If the gas was cool to start with, it could have been fed along filaments of the network into the dark matter clumps, accreting into large, cool, orderly disc galaxies.

 

But the only way to confirm this model is through observational evidence, so the researchers went looking, using the light of even more distant galaxies, called quasars, to illuminate the way.

Distant galaxies are very hard to see, but quasars are among the most luminous objects in the Universe – galaxies lit by an active supermassive black hole, the space around it blasting out radiation as it feeds. The team turned ALMA’s powerful capabilities to these distant quasars, looking for signatures in their light that showed that it had passed through a gas-filled galaxy on the way.

They found it. The light from one of the quasars they imaged had passed through a region rich with hydrogen – the signature of the Wolfe Disk.

And there was something else. The light on one side of the disc was compressed, or blueshifted. We see this when something is moving towards us. And the light from the other side was stretched, or redshifted – moving away from us. The object was rotating.

Those Doppler shifts, as they are known, then allowed the researchers to calculate the velocity of the galaxy’s rotation: around 272 kilometres per second.

What’s even more wild is that the team believes the Wolfe Disk isn’t one of a kind. 

“The fact that we found the Wolfe Disk using this method, tells us that it belongs to the normal population of galaxies present at early times,” Neeleman said.

“When our newest observations with ALMA surprisingly showed that it is rotating, we realised that early rotating disk galaxies are not as rare as we thought and that there should be a lot more of them out there.”

The team will continue their search for these galaxies to find out just how common cold accretion was in the early Universe.

The research has been published in Nature.

 

Continue Reading

Science

NASA’s head of human spaceflight abruptly resigns, citing ‘mistake’ – CNN

Published

on

By

NASA’s head of human spaceflight abruptly resigns, citing ‘mistake’ – CNN_5ec5b2b4e863d.jpeg

His departure was effective on Monday.

The incident in question was related to the Artemis Program, a source familiar with the matter told CNN Business.
The Artemis Program seeks to return astronauts to the moon by 2024, which was announced by the Trump administration last year and has been criticized as unrealistic. The source familiar with the reason for Loverro’s departure said the issue centered on contracts that were awarded earlier this year for development of lunar landers, or vehicles that can carry astronauts to the moon’s surface.

When reached by phone Tuesday evening, Loverro declined to comment on the reason for his departure.

Loverro began serving in his role as the head of NASA’s human spaceflight programs in December, replacing William Gerstenmaier, who served in the role for more than a decade. In his nearly 700-word note, Loverro told NASA workers only that leaders are “called on to take risks” and added that, “I took such a risk earlier in the year because I judged it necessary to fulfill our mission.”

“Now, over the balance of time, it is clear that I made a mistake in that choice for which I alone must bear the consequences,” Loverro wrote. “And therefore, it is with a very, very heavy heart that I write to you today to let you know that I have resigned from NASA effective May 18th, 2020.”

NASA’s Office of the Inspector General announced an audit of the agency’s acquisition strategy for the Artemis program in March, though it’s unclear if that review was related to Loverro’s departure. It’s also unclear exactly what role Loverro played in the selection process.
The source familiar with the matter, who asked to remain anonymous because the space agency has not yet publicized details, told CNN Business that the incident in question was unrelated to NASA’s historic milestone next week when SpaceX, NASA’s partner in the Commercial Crew Program, launches two astronauts to the International Space Station. That mission will mark the first time since 2011 that humans have launched into orbit from US soil, and Loverro was slated to preside over a final technical review meeting on Thursday, ahead of launch on May 27. Steve Jurczyk, NASA’s associate administrator, will take over Loverro’s role at that meeting, according to NASA.

Ken Bowersox, NASA’s acting deputy associate administrator for human exploration and operations, will become NASA’s interim head of human spaceflight.

Loverro’s exit immediately raised some eyebrows on Capitol Hill.

Meet the NASA astronauts who will fly on historic SpaceX mission

Congresswoman Eddie Bernice Johnson, a Democrat from Texas who chairs the House space and science committee, said in a statement that she was “shocked” by the news.

“I trust that NASA Administrator Bridenstine will ensure that the right decision is made as to whether or not to delay the launch attempt,” Johnson said. “Beyond that, Mr. Loverro’s resignation is another troubling indication that the Artemis Moon-Mars initiative is still not on stable footing. I look forward to clarification from NASA as to the reasons for this latest personnel action.”

Kendra Horn, a Democrat from Oklahoma who chairs a House subcommittee on space, said in a tweet Tuesday that she is “deeply concerned over this sudden resignation, especially eight days before the first scheduled launch of US astronauts on US soil in almost a decade.”

The timing of Loverro’s departure was related to when Jurczyk, the associate administrator, made a recommendation to NASA Administrator Jim Bridenstine, the source said. It was unrelated to next week’s Crew Dragon launch, the source added.

Jurczyk was the source selection officer for the Artemis lunar lander contract awards, according to public documents.

In announcing Loverro’s appointment in October, NASA chief Jim Bridenstine called Loverro “a respected strategic leader in both civilian and defense programs” who “will be of great benefit to NASA at this critical time in our final development of human spaceflight systems for both Commercial Crew and Artemis.”

An agency-wide email sent on Tuesday said Loverro “hit the ground running” after his appointment in 2019 and had made “significant progress in his time at NASA.”

“His leadership of [NASA’s Human Exploration and Operations] has moved us closer to our goal of landing the first woman and the next man on the moon in 2024,” the email said. It said his resignation was effective immediately, though it did not provide details on the reason for his exit.

A NASA spokesperson declined to comment.

Loverro told CNN Business he is “100% confident” that leadership will be able to carry out the SpaceX mission. He added that he believes NASA’s ambitious human spaceflight goals are “doable.” “But,” he added, “it will take risk takers to get us there, and I hope folks who step in my shoes will continue to take risks.”

Next week’s SpaceX launch will mark the space agency’s highest-profile mission since the Space Shuttle program ended in 2011. SpaceX, which has a multibillion-dollar contract under NASA’s Commercial Crew Program, has worked for the better part of a decade to ready its Dragon spacecraft for crewed flights to the International Space Station. Since the Shuttle retired, NASA has had to rely on Russia for rides to the ISS.

Continue Reading

Science

In an orange swirl, astronomers say humanity has its first look at the birth of a planet

Published

on

By

In an orange swirl, astronomers say humanity has its first look at the birth of a planet_5ec5b2aa94bef.jpeg

An image of a mesmerizing cosmic spiral, twisting and swirling around a galactic maw, may be the first direct evidence of the birth of a planet ever captured by humanity.

The European Southern Observatory released a picture Wednesday of what astronomers believe shows the process of cosmic matter at a gravitational tipping point, collapsing into a new world around a nearby star.

Astronomers said the dramatic scene offers a rare glimpse into the formation of a baby planet, which could help scientists better understand how planets come to exist around stars.

“Thousands of exoplanets have been identified so far, but little is known about how they form,” the lead author of a study detailing the discovery, Anthony Boccaletti, an astronomer at the Observatoire de Paris in France, said in a statement.

Planets are thought to form out of the massive discs of gas and dust that surround young stars. As tiny specks of dust circle a star and collide with one another, some material starts to fuse, much like how rolling a snowball through more snow will eventually yield a bigger snowball. After billions of years, the clumps of material become large enough that the force of gravity shapes them into planets.

The new image peers into the disc of material around a young star known as AB Aurigae, which is 520 light-years from Earth in the constellation of Auriga. Amid the hypnotic spiral arms is a “twist,” visible in the photo as a bright yellow region in the center, that is thought to be a sign of a planet being born, said Emmanuel Di Folco, a researcher at the Astrophysics Laboratory of Bordeaux in France, who participated in the study.

When a planet forms, the clumps of material create wavelike perturbations in the gas- and dust-filled disc around a star, “somewhat like the wake of a boat on a lake,” Di Folco said.

The bright region at the center of the new image is thought to be evidence of such a disturbance, which had been predicted in models of planetary birth.

Download the NBC News app for breaking news and alerts

“The twist is expected from some theoretical models of planet formation,” said Anne Dutrey, an astronomer at the Astrophysics Laboratory of Bordeaux and co-author of the study, published Wednesday in the journal Astronomy & Astrophysics. “It corresponds to the connection of two spirals — one winding inwards of the planet’s orbit, the other expanding outwards — which join at the planet location.”

The new observations of the baby planet were made in 2019 and early 2020 by the European Southern Observatory’s Very Large Telescope in the Atacama Desert in northern Chile. The research team, made up of astronomers from France, Taiwan, the U.S. and Belgium, said the images are the deepest observations of the AB Aurigae system made to date.

Continue Reading

Trending