Tuesday, March 30, 2021

Hubble Team Releases Reprocessed Image of Veil Nebula

A small portion of the Veil Nebula, which is part of a supernova remnant called the Cygnus Loop, was featured in previous Hubble photos, but now new processing techniques have been applied, bringing out fine details of the Veil Nebula’s delicate threads and filaments of ionized gas. The Cygnus Loop is a large donut-shaped nebula located approximately 2,400 light-years away from Earth. Also known as W78 and Sharpless 103, it is actually an expanding blast wave from a supernova explosion that occurred about 15,000 years ago. Its name comes from its position in the northern constellation of Cygnus, where it covers an area 36 times larger than the full Moon. The visual portion of the supernova remnant is known as the Veil Nebula, also called the Cirrus Nebula or the Filamentary Nebula. “The nebula’s progenitor star — which was 20 times the mass of the Sun — lived fast and died young, ending its life in a cataclysmic release of energy,” Hubble astronomers said. “Despite this stellar violence, the shockwaves and debris from the supernova sculpted the nebula’s delicate tracery of ionized gas — creating a scene of surprising astronomical beauty.”

This Hubble image shows a small portion of the Veil Nebula, which is located 2,400 light-years away in the constellation of Cygnus. Image credit: NASA / ESA / Hubble / Z. Levay.

To create this colorful image, of the Veil Nebula observations taken by Hubble’s Wide Field Camera 3 (WFC3) instrument through five different filters were used.

The new post-processing methods have further enhanced details of emissions from doubly ionized oxygen (blue), ionized hydrogen and ionized nitrogen (red).

Sunday, March 28, 2021

NASA Developing Sustainable Solar Power Sources for the Moon; Will Support Lunar Rovers, Missions by Decade-End

In a bid to establish artificial power sources on the Moon, American space agency NASA is working with several commercial companies in order to design vertically deployable solar array systems. Once deployed, this reliable, sustainable power source would support lunar habitats, rovers, and even construction systems for future robotic and crewed missions. These solar array systems will be autonomously deployable up to 32 feet high, and retractable for relocation if necessary. The designs will also be created in a way that ensures the systems remain stable on steep terrain, be resistant to abrasive lunar dust, and minimise both mass and packaged volume to aid in the system’s delivery to the lunar surface, as per the NASA statement. These vertically deployable systems will differ from the existing space-rated solar array structures and deployment systems, which are designed for horizontal surface deployment or microgravity usage. This is quite intentional, as the vertical position and the height of the energy source will help prevent loss of power at the lunar poles, where the Sun does not rise very far above the horizon. When low-angled sunlight hits rocky formations like hills and slopes near the lunar poles, it casts a shadow over the surface—shadows that can block horizontally structured solar arrays from obtaining light. A tall, vertical solar power structure, however, would increase the likelihood of getting uninterrupted light. Therefore, these solar power designs could help enable continuous power for habitats and operations, even in areas shaded by rocky features.


According to Chuck Taylor, who is leading vertical solar array development at NASA’s Langley Research Centre, exploring ways to make solar arrays more efficient when they encounter lunar shading is also driving possible applications on Earth. Therefore, home and business owners could end up benefiting from adapted designs, which increase the efficiency of rooftop solar arrays that are occasionally shaded due to trees or tall buildings.

Meanwhile, this power source technology will be a part of the Artemis program, wherein NASA will land the first woman and next man on the Moon by the year 2024, using innovative technologies to explore more of the lunar surface than ever before. This will not only establish humankind’s sustainable presence at the lunar South Pole, but also pave the way for sustainable exploration by the end of the decade.

NASA has selected five companies for base period contracts to complete their vertical solar array designs and conduct analysis. These include Astrobotic Technology, ATK Space Systems (Northrop Grumman), Honeybee Robotics, Lockheed Martin, and Space Systems Loral (Maxar Technologies).

“We are thrilled with the proposals received and even more excited to see the designs that result from the base effort,” said Niki Werkheiser, director of technology maturation in NASA’s Space Technology Mission Directorate (STMD). “Having reliable power sources on the Moon is key to almost anything we do on the surface. By working with five different companies to design these prototype systems, we are effectively mitigating the risk that is inherent to developing such cutting-edge technologies.”

All five companies will submit their system designs, analysis, and data at the end of the 12-month fixed-price base contracts, valued at up to $700,000 each. NASA will then select up to two companies and provide them with additional funding of up to $7.5 million each to build prototypes and perform environmental testing.

The ultimate goal of this partnership will be to deploy one of the systems on the Moon’s South Pole near the end of this decade.

Tuesday, March 23, 2021

Astronomers Puzzled After Hubble View of Torrential Outflows From Infant Stars Blows Hole in Current Theories


Study Finds That Cavities Sculpted by Stellar Outflows Did Not Expand Over Time. Stars aren’t shy about announcing their births. As they are born from the collapse of giant clouds of hydrogen gas and begin to grow, they launch hurricane-like winds and spinning, lawn-sprinkler-style jets shooting off in opposite directions. This action carves out huge cavities in the giant gas clouds. Astronomers thought these stellar temper tantrums would eventually clear out the surrounding gas cloud, halting the star’s growth. But in a comprehensive analysis of 304 fledgling stars in the Orion Complex, the nearest major star-forming region to Earth, researchers discovered that gas-clearing by a star’s outflow may not be as important in determining its final mass as conventional theories suggest. Their study was based on previously collected data from NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope. The study leaves astronomers still wondering why star formation is so inefficient. Only 30% of a hydrogen gas cloud’s initial mass winds up as a newborn star.

These four images taken by NASA’s Hubble Space Telescope reveal the chaotic birth of stars in the Orion complex, the nearest major star-forming region to Earth. The protostars were photographed in near-infrared light by Hubble’s Wide Field Camera 3. The images were taken November 14, 2009, and January 25, February 11, and August 11, 2010. Credit: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)


Though our galaxy is an immense city of at least 200 billion stars, the details of how they formed remain largely cloaked in mystery.


Scientists know that stars form from the collapse of huge hydrogen clouds that are squeezed under gravity to the point where nuclear fusion ignites. But only about 30 percent of the cloud’s initial mass winds up as a newborn star. Where does the rest of the hydrogen go during such a terribly inefficient process?

It has been assumed that a newly forming star blows off a lot of hot gas through light-saber-shaped outflowing jets and hurricane-like winds launched from the encircling disk by powerful magnetic fields. These fireworks should squelch further growth of the central star. But a new, comprehensive Hubble survey shows that this most common explanation doesn’t seem to work, leaving astronomers puzzled.

Researchers used data previously collected from NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope to analyze 304 developing stars, called protostars, in the Orion Complex, the nearest major star-forming region to Earth. (Spitzer and Herschel are no longer operational.)

This ground-based image offers a wide view of the entire Orion cloud complex, the closest major star-forming region to Earth.
The red material is hydrogen gas ionized and heated by ultraviolet radiation from massive stars in Orion. The stars are forming in clouds of cold hydrogen gas that are either invisible or appear as dark regions in this image. The crescent shape is called Barnard’s Loop and partly wraps around the winter constellation figure of Orion the Hunter. The hunter’s belt is the diagonal chain of three stars at image center. His feet are the bright stars Saiph (bottom left) and Rigel (bottom right).
This landscape encompasses tens of thousands of newly forming stars bursting to life. Many are still encased in their natal cocoons of gas and dust and only seen in infrared light.
The undulating line of yellow dots, beginning at lower left, is a superimposed image of 304 nascent stars taken by NASA’s Hubble Space Telescope.
Researchers used NASA’s Hubble and Spitzer space telescopes and the European Space Agency’s Herschel Space Telescope to analyze how young stars’ powerful outflows carve out cavities in the vast gas clouds. The study is the largest-ever survey of developing stars.
Credit: Image courtesy of R. B. Andreo, DeepSkyColors.com; Data Overlay: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)



In this largest-ever survey of nascent stars to date, researchers are finding that gas — clearing by a star’s outflow may not be as important in determining its final mass as conventional theories suggest. The researchers’ goal was to determine whether stellar outflows halt the infall of gas onto a star and stop it from growing.

Instead, they found that the cavities in the surrounding gas cloud sculpted by a forming star’s outflow did not grow regularly as they matured, as theories propose.

“In one stellar formation model, if you start out with a small cavity, as the protostar rapidly becomes more evolved, its outflow creates an ever-larger cavity until the surrounding gas is eventually blown away, leaving an isolated star,” explained lead researcher Nolan Habel of the University of Toledo in Ohio.

“Our observations indicate there is no progressive growth that we can find, so the cavities are not growing until they push out all of the mass in the cloud. So, there must be some other process going on that gets rid of the gas that doesn’t end up in the star.”

The team’s results will appear in an upcoming issue of The Astrophysical Journal.


A Star is Born

During a star’s relatively brief birthing stage, lasting only about 500,000 years, the star quickly bulks up on mass. What gets messy is that, as the star grows, it launches a wind, as well as a pair of spinning, lawn-sprinkler-style jets shooting off in opposite directions. These outflows begin to eat away at the surrounding cloud, creating cavities in the gas.

Popular theories predict that as the young star evolves and the outflows continue, the cavities grow wider until the entire gas cloud around the star is completely pushed away. With its gas tank empty, the star stops accreting mass – in other words, it stops growing.

These four images taken by NASA’s Hubble Space Telescope reveal the chaotic birth of stars in the Orion complex, the nearest major star-forming region to Earth. The protostars were photographed in near-infrared light by Hubble’s Wide Field Camera 3. Credit: NASA, ESA, STScI, N. Habel and S. T. Megeath (University of Toledo)


To look for cavity growth, the researchers first sorted the protostars by age by analyzing Herschel and Spitzer data of each star’s light output. The protostars in the Hubble observations were also observed as part of the Herschel telescope’s Herschel Orion Protostar Survey.

Then the astronomers observed the cavities in near-infrared light with Hubble’s Near-infrared Camera and Multi-object Spectrometer and Wide Field Camera 3. The observations were taken between 2008 and 2017. Although the stars themselves are shrouded in dust, they emit powerful radiation which strikes the cavity walls and scatters off dust grains, illuminating the gaps in the gaseous envelopes in infrared light.

The Hubble images reveal the details of the cavities produced by protostars at various stages of evolution. Habel’s team used the images to measure the structures’ shapes and estimate the volumes of gas cleared out to form the cavities. From this analysis, they could estimate the amount of mass that had been cleared out by the stars’ outbursts.

“We find that at the end of the protostellar phase, where most of the gas has fallen from the surrounding cloud onto the star, a number of young stars still have fairly narrow cavities,” said team member Tom Megeath of the University of Toledo. “So, this picture that is still commonly held of what determines the mass of a star and what halts the infall of gas is that this growing outflow cavity scoops up all of the gas. This has been pretty fundamental to our idea of how star formation proceeds, but it just doesn’t seem to fit the data here.”

Future telescopes such as NASA’s upcoming James Webb Space Telescope will probe deeper into a protostar’s formation process. Webb spectroscopic observations will observe the inner regions of disks surrounding protostars in infrared light, looking for jets in the youngest sources. Webb also will help astronomers measure the accretion rate of material from the disk onto the star, and study how the inner disk is interacting with the outflow.

Reference: “An HST Survey of Protostellar Outflow Cavities: Does Feedback Clear Envelopes?” by Nolan M. Habel, S. Thomas Megeath, Joseph Jon Booker, William J. Fischer, Marina Kounkel, Charles Poteet, Elise Furlan, Amelia Stutz, P. Manoj, John J. Tobin, Zsofia Nagy, Riwaj Pokhrel and Dan Watson, Accepted, The Astrophysical Journal.


Saturday, March 20, 2021

Spacecraft in a ‘warp bubble’ could travel faster than light, claims physicist

Albert Einstein’s special theory of relativity famously dictates that no known object can travel faster than the speed of light in vacuum, which is 299,792 km/s. This speed limit makes it unlikely that humans will ever be able to send spacecraft to explore beyond our local area of the Milky Way. However, new research by Erik Lentz at the University of Göttingen suggests a way beyond this limit. The catch is that his scheme requires vast amounts of energy and it may not be able to propel a spacecraft. Lentz proposes that conventional energy sources could be capable of arranging the structure of spacetime in the form of a soliton – a robust singular wave. This soliton would act like a “warp bubble”, contracting space in front of it and expanding space behind. Unlike objects within spacetime, spacetime itself can bend, expand or warp at any speed. Therefore, a spacecraft contained in a hyper-fast bubble could arrive at its destination faster than light would in normal space without breaking any physical laws, even Einstein’s cosmic speed limit.


Negative energy

The idea of creating warp bubbles is not new, it was first proposed in 1994 by the Mexican physicist Miguel Alcubierre who dubbed them “warp drives” in homage to the sci-fi series Star Trek. However, until Lentz’s research it was thought that the only way to produce a warp drive was by generating vast amounts of negative energy – perhaps by using some sort of undiscovered exotic matter or by the manipulation of dark energy. To get around this problem, Lentz constructed an unexplored geometric structure of spacetime to derive a new family of solutions to Einstein’s general relativity equations called positive-energy solitons.

Though Lentz’s solitons appear to conform to Einstein’s general theory of relativity and remove the need to create negative energy, space agencies will not be building warp drives any time soon, if ever. Part of the reason is that Lentz’s positive-energy warp drive requires a huge amount of energy. A 100 m radius spacecraft would require the energy equivalent to “hundreds of times of the mass of the planet Jupiter,” according to Lentz. He adds that to be practical, this requirement would have to be reduced by about 30 orders of magnitude to be on par with the output of a modern nuclear fission reactor. Lentz is currently exploring existing energy-saving schemes to see if the energy required can be reduced to a practical level.

Any warp drive would also need to overcome several other serious issues. Alcubierre, who regards Lentz’s work as a “significant development”, cites the “horizon problem” as one of the most pernicious: “A warp bubble travelling faster than light cannot be created from inside the bubble, as the leading edge of the bubble would be beyond the reach of a spaceship sitting at its centre,” he explains. “The problem is that you need energy to deform space all the way to the very edge of the bubble, and the ship simply can’t put it there.”


Spacecraft doubts

Lentz describes his calculations in Classical and Quantum Gravity, where other recent research on the topic is outlined in an accepted manuscript from Advanced Propulsion Laboratory researchers Alexey Bobrick and Gianni Martire. The duo describes a general model for a warp drive incorporating all existing positive-energy and negative-energy warp drive schemes, except Lentz’s which they say “likely forms a new class of warp drive spacetimes”.

However, they argue that a Lentz-type warp drive is like any other type of warp drive in the sense that, at its core, it is a shell of regular material and therefore subject to Einstein’s cosmic speed limit, concluding that “there is no known way of accelerating a warp drive beyond the speed of light”.

Though he recognizes these huge hurdles to building a warp drive, Lentz feels they are not insurmountable. “This work has moved the problem of faster-than-light travel one step away from theoretical research in fundamental physics and closer to engineering,” he says.

After addressing energy requirements, Lentz plans to “devise a means of creating and accelerating (and dissipating and decelerating) the positive-energy solitons from their constituent matter sources,” then confirm the existence of small and slow solitons in a laboratory, and finally address the horizon problem. “This will be important to passing the speed of light with a fully autonomous soliton,” he says.

Friday, March 12, 2021

Newfound super-Earth alien planet whips around its star every 0.67 days

We keep getting reminders that the Milky Way's planetary diversity dwarfs what we see in our own solar system. The newfound exoplanet TOI-1685 b is yet another case in point. Astronomers found it circling a dim red dwarf star about 122 light-years from Earth. "Circling" is too ordinary a world for TOI-1685 b's motion, however; the alien world whips around its parent star once every 0.67 Earth days. Red dwarfs, also known as M dwarfs, are much smaller and dimmer than Earth's sun, but TOI-1685 b's extreme proximity to its host star, called TOI-1685, makes it a very toasty world nonetheless. The discovery team estimates its surface temperature to be around 1,465 degrees Fahrenheit (796 degrees Celsius). The researchers, led by Paz Bluhm of Heidelberg University in Germany, first spotted TOI-1685 b in observations made by NASA's Transiting Exoplanet Survey Satellite (TESS). As its name suggests, TESS looks for transits, the tiny brightness dips caused by planets crossing their host stars' faces from the Earth-orbiting spacecraft's perspective. TESS noted such a dip around the red dwarf TOI-1685. Bluhm and her colleagues then confirmed the planet's existence using data gathered by the CARMENES spectrograph instrument, which is installed on the 3.5-meter telescope at the Calar Alto Observatory in Spain. (CARMENES is short for "Calar Alto high-Resolution search for M dwarfs with Exo-earths with Near-infrared and optical Echelle spectrographs.)


CARMENES hunts for planets using the radial velocity, or Doppler, method — looking for little wobbles in a star's motion caused by the gravitational tug of an orbiting planet.


The combined data allowed the team to determine that TOI-1685 b is a "super-Earth" about 1.7 times bigger, and 3.8 times more massive, than our home planet. The resulting bulk density — about 4.2 grams per cubic centimeter, or 0.15 lbs. per cubic inch — makes TOI-1685 b "the least dense ultra-short period planet around an M dwarf known to date," Bluhm and her colleagues wrote in the discovery paper, which you can read for free on the online preprint site arXiv.org. (The paper has not yet been published in a peer-reviewed journal.)

For perspective: Earth's bulk density is about 5.5 grams per cubic centimeter, or 0.20 lbs. per cubic inch.

The fact that TOI-1685 b transits and is quite warm makes it a good candidate for follow-up study by other instruments, the researchers wrote. In that regard, TOI-1685 b is similar to another recent exoplanet find made using TESS and CARMENES data, Gliese 486 b.

Bluhm and her team also saw another signal in the CARMENES TOI-1685 data, which could indicate a second planet in the system that orbits once every nine Earth days. If this candidate planet exists, it doesn't transit, because TESS recorded no corresponding signal, the researchers wrote.



Wednesday, March 10, 2021

NASA, Blue Origin Partner to Bring Lunar Gravity Conditions Closer to Earth

At one-sixth that of Earth, the unique gravity of the lunar surface is one of the many variable conditions that technologies bound for the Moon will need to perform well in. NASA will soon have more options for testing those innovations in lunar gravity thanks to a collaboration with Blue Origin to bring new testing capabilities to the company’s New Shepard reusable suborbital rocket system. Currently, NASA can approximate the Moon’s gravity on parabolic flights and in centrifuges on suborbital vehicles – both invaluable options for maturing promising innovations. But these methods provide only seconds of lunar gravity exposure at a time or limit the payload size, compelling NASA to explore longer-duration and larger size options. Blue Origin’s new lunar gravity testing capability – projected to be available in late 2022 – is answering that need. New Shepard’s upgrades will allow the vehicle to use its reaction control system to impart a rotation on the capsule. As a result, the entire capsule essentially acts as a large centrifuge to create artificial gravity environments for the payloads inside. Blue Origin’s first flight of this capability will target 11 rotations per minute to provide more than two minutes of continuous lunar gravity, exposing the technologies to this challenging but difficult-to-test condition.


This new capability is made possible with the help of development funding and early purchase of payload space by NASA as part of its strategic investment in the U.S. spaceflight industry. The lunar gravity simulation will enable the agency to test and de-risk innovations critical to achieving the goals of the Artemis program, as well as lunar surface exploration and Moon-bound commercial applications.

“NASA is pleased to be among the first customers to take advantage of this new capability,” said Christopher Baker, program executive for the Flight Opportunities program at NASA Headquarters in Washington. “One of the constant challenges with living and working in space is reduced gravity. Many systems designed for use on Earth simply do not work the same elsewhere. A wide range of tools we need for the Moon and Mars could benefit from testing in partial gravity, including technologies for in-situ resource utilization, regolith mining, and environmental control and life support systems.”

New Shepard is currently among the commercial flight platforms available for technology flight testing contracted by NASA’s Flight Opportunities program. The program has helped mature hundreds of promising space-based technologies from NASA, industry, and academia by putting them through their paces on commercial suborbital vehicles before they move on to higher risk orbital missions – on CubeSats, the International Space Station, the Moon, or even Mars. New Shepard’s future lunar gravity capability will expand the suborbital flight test offerings not only for the company but for the Flight Opportunities program as well, adding to the specialized testing available for the technologies selected for testing by the program each year.

“Humanity has been dreaming about artificial gravity since the earliest days of spaceflight,” said Erika Wagner, PhD, New Shepard director of payloads at Blue Origin. “It’s exciting to be partnering with NASA to create this one-of-a-kind capability to explore the science and technology we will need for future human space exploration.”



About Flight Opportunities

The Flight Opportunities program is funded by NASA’s Space Technology Mission Directorate (STMD) and managed at NASA's Armstrong Flight Research Center in Edwards, California. NASA's Ames Research Center in California's Silicon Valley manages the solicitation and evaluation of technologies to be tested and demonstrated on commercial flight vehicles.

Friday, March 5, 2021

Hubble: 30 Years and Counting

It's March 2021 and in about another month the Hubble Space Telescope will celebrate 31 years in space observing the universe. In this image celebrating Hubble's 30th birthday, the giant red nebula (NGC 2014) and its smaller blue neighbor (NGC 2020) are part of a vast star-forming region in the Large Magellanic Cloud, a satellite galaxy of the Milky Way, located 163,000 light-years away. The image is nicknamed the "Cosmic Reef," because NGC 2014 resembles part of a coral reef floating in a vast sea of stars. Some of the stars in NGC 2014 are monsters. The nebula's sparkling centerpiece is a grouping of bright, hefty stars, each 10 to 20 times more massive than our Sun. The seemingly isolated blue nebula at lower left (NGC 2020) has been created by a solitary mammoth star 200,000 times brighter than our Sun. The blue gas was ejected by the star through a series of eruptive events during which it lost part of its outer envelope of material. 

NGC 2014

Image Credit: NASA, ESA and STScI

Monday, March 1, 2021

Who is controlling Nasa's Mars rover? Indian-origin scientist from his flat in London

Nasa's Perseverance Mars rover made history earlier this year by successfully landing on the red planet. Nearly seven months after its takeoff, the Perseverance rover landed at Mars' Jezero Crater on February 19. Would you believe that Nasa's life-on-Mars mission valued at $3 billion is being controlled by an Indian-origin doctor from his one-bedroom apartment in London? Professor Sanjeev Gupta, a scientist with Nasa is controlling the Mars rover 'Perseverance' from his flat in south London. Professor Gupta was supposed to be at mission control in California but the Covid-19 pandemic restricted him to his flat above a hairdresser in Lewisham. "I should be at the Jet Propulsion Laboratory in California, in a series of offices each one about three times bigger than this lounge, full of hundreds of scientists and engineers with their heads buried in laptops surrounded by large screens," Professor Sanjeev Gupta told the Daily Mail. 

Professor Sanjeev Gupta

When he found out that he would not be able to work out of mission control in California, Professor Sanjeev Gupta decided to rent a one-bedroom flat in Lewisham.

I did not want to disturb the sleep of my wife and children, he told the UK publication.

Professor Gupta has turned his rented apartment into a mini control centre with at least five computers and two other screens for video conferences with fellow scientists at Nasa.

One of Nasa's leading scientists working on the Perseverance Mars rover, Professor Gupta is a geology expert at London's Imperial College.

Accompanied by a team of nearly 400 scientists, Professor Sanjeev Gupta is directing the Perseverance rover to drill for samples on Mars. These samples will be transported back to Earth by 2027.