Help NASA decide where to land on asteroid

This image shows a view of asteroid Bennu’s surface in a region near the equator. It was taken by NASA’s OSIRIS-REx spacecraft on March 21, 2019, from a distance of 2.2 miles (3.5 km). For scale, the light-colored rock in the upper left corner of the image is 24 ft (7.4 m) wide. Image via NASA/Goddard/University of Arizona.

You can help NASA’s OSIRIS-REx mission to the asteroid Bennu choose its sample collection site on the asteroid – and also look for anything else that might be scientifically interesting.

The OSIRIS-REx spacecraft has been at Bennu since December 3, 2018, and is now orbiting the asteroid. The mission’s main goal is to obtain a sample from the asteroid and return the sample to Earth for a detailed analysis. The mission team needs to find a landing and sample collection site that’s safe, conducive to sample collection and worthy of closer study.

One of the big challenges, which the team discovered after the spacecraft arrived at the asteroid, is that Bennu has an extremely rocky surface and each boulder presents a danger to the spacecraft’s safety. To expedite the sample selection process, the team is asking citizen scientist volunteers to develop a hazard map by counting boulders.

Between now and July 10, you can volunteer as a Bennu mapper here.

If you volunteer, you’ll be doing the same tasks that planetary scientists do – measuring Bennu’s boulders and mapping its rocks and craters – through the use of a simple web interface. NASA said the boulder mapping work involves a high degree of precision, but it’s not difficult. You can also mark other scientifically interesting features on the asteroid for further investigation.

For this effort, NASA is partnering with a project called CosmoQuest. To use the CosmoQuest mapping app, you need a computer with a large screen and a mouse or trackpad capable of making precise marks. There’s a tutorial to help you get started, as well as additional user assistance and livestreaming sessions.

Rich Burns is OSIRIS-REx project manager at NASA Goddard Space Flight Center. He said in a statement:

Bennu has surprised us with an abundance of boulders. We ask for citizen scientists’ help to evaluate this rugged terrain so that we can keep our spacecraft safe during sample collection operations.

Volunteer as a Bennu mapper here.

The Bennu mapping campaign continues through July 10, when the mission begins the sample site selection process. Once primary and secondary sites are selected, the spacecraft will begin closer reconnaissance to map the two sites to sub-centimeter resolution. The mission’s sampling maneuver is scheduled for July 2020, and the spacecraft will return to Earth with its cargo in September 2023.

This image shows the wide variety of boulder shapes, sizes and compositions found on asteroid Bennu. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 28 from a distance of 2.1 miles (3.4 km). The field of view is 162.7 ft (49.6 m). For scale, the large, light-colored boulder at the top of the image is 15.7 ft (4.8 m) tall. Image via NASA/Goddard/University of Arizona.

Via NASA

from EarthSky http://bit.ly/2YTm5Ds

This image shows a view of asteroid Bennu’s surface in a region near the equator. It was taken by NASA’s OSIRIS-REx spacecraft on March 21, 2019, from a distance of 2.2 miles (3.5 km). For scale, the light-colored rock in the upper left corner of the image is 24 ft (7.4 m) wide. Image via NASA/Goddard/University of Arizona.

You can help NASA’s OSIRIS-REx mission to the asteroid Bennu choose its sample collection site on the asteroid – and also look for anything else that might be scientifically interesting.

The OSIRIS-REx spacecraft has been at Bennu since December 3, 2018, and is now orbiting the asteroid. The mission’s main goal is to obtain a sample from the asteroid and return the sample to Earth for a detailed analysis. The mission team needs to find a landing and sample collection site that’s safe, conducive to sample collection and worthy of closer study.

One of the big challenges, which the team discovered after the spacecraft arrived at the asteroid, is that Bennu has an extremely rocky surface and each boulder presents a danger to the spacecraft’s safety. To expedite the sample selection process, the team is asking citizen scientist volunteers to develop a hazard map by counting boulders.

Between now and July 10, you can volunteer as a Bennu mapper here.

If you volunteer, you’ll be doing the same tasks that planetary scientists do – measuring Bennu’s boulders and mapping its rocks and craters – through the use of a simple web interface. NASA said the boulder mapping work involves a high degree of precision, but it’s not difficult. You can also mark other scientifically interesting features on the asteroid for further investigation.

For this effort, NASA is partnering with a project called CosmoQuest. To use the CosmoQuest mapping app, you need a computer with a large screen and a mouse or trackpad capable of making precise marks. There’s a tutorial to help you get started, as well as additional user assistance and livestreaming sessions.

Rich Burns is OSIRIS-REx project manager at NASA Goddard Space Flight Center. He said in a statement:

Bennu has surprised us with an abundance of boulders. We ask for citizen scientists’ help to evaluate this rugged terrain so that we can keep our spacecraft safe during sample collection operations.

Volunteer as a Bennu mapper here.

The Bennu mapping campaign continues through July 10, when the mission begins the sample site selection process. Once primary and secondary sites are selected, the spacecraft will begin closer reconnaissance to map the two sites to sub-centimeter resolution. The mission’s sampling maneuver is scheduled for July 2020, and the spacecraft will return to Earth with its cargo in September 2023.

This image shows the wide variety of boulder shapes, sizes and compositions found on asteroid Bennu. It was taken by the PolyCam camera on NASA’s OSIRIS-REx spacecraft on March 28 from a distance of 2.1 miles (3.4 km). The field of view is 162.7 ft (49.6 m). For scale, the large, light-colored boulder at the top of the image is 15.7 ft (4.8 m) tall. Image via NASA/Goddard/University of Arizona.

Via NASA

from EarthSky http://bit.ly/2YTm5Ds

Astronomers find 18 more Earth-sized exoplanets in Kepler data

Size comparison with Earth, Neptune and the 18 newly discovered exoplanets. Wouldn’t it be grand to see surface details on these new worlds? Image via NASA/JPL (Neptune), NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring (Earth), MPS/René Heller.

Exoplanets about the same size as Earth can be some of the most difficult to detect, but their numbers are growing, and now scientists from the Max Planck Institute for Solar System Research, the Georg August University of Göttingen and the Sonneberg Observatory have added 18 more exoplanets to the ever-expanding list (as of May 1, 2019, there were 4,058 confirmed planets in 3,033 systems, with 658 systems having more than one planet). All 18 new exoplanets were found during a re-analysis of data from the highly effective Kepler Space Telescope planet-hunting mission, using a new, more sensitive search algorithm called Transit Least-Squares.

The first fruits of the new algorithm may be found in peer-reviewed findings published in the journal Astronomy & Astrophysics in two new papers, here and here. The first paper, focusing on exoplanet K2-32e, was published a few weeks ago, and the second paper regarding the other 17 exoplanets was published on May 21, 2019.

These newly-found worlds are some of the smallest detected so far. They range in size from only 69 percent of the diameter of Earth (EPIC 201497682.03, 831 light-years away) to just slightly more than twice as large as Earth. All of them were hiding in the Kepler data, and were not found in previous searches because the search algorithms were not sensitive enough. Like many other exoplanet hunters, Kepler used the transit method, where a planet passes in front of its star, as seen from our vantage point here on Earth. As the planet transits in front of the star, it blocks out a tiny amount of the light coming from the star, which can then be measured by astronomers. As René Heller of Max Planck Institute, first author of both papers, explained:

Standard search algorithms attempt to identify sudden drops in brightness. In reality, however, a stellar disk appears slightly darker at the edge than in the center. When a planet moves in front of a star, it therefore initially blocks less starlight than at the mid-time of the transit. The maximum dimming of the star occurs in the center of the transit just before the star becomes gradually brighter again.

Artist’s concept of Kepler-186f, the first Earth-sized exoplanet found orbiting in the habitable zone of its star. A growing number of such worlds have been found in recent years, including the 18 new exoplanets just announced. Image via NASA Ames/JPL-Caltech/T. Pyle.

As could be expected, larger planets are the easiest to detect, since they block out more light from their stars during a transit. The amount of light blocked by smaller planets can easily be missed, as it can be hard to distinguish from the natural brightness fluctuations of the star itself and the background noise that is part of these kinds of observations.

The new Transit Least-Squares algorithm improves the sensitivity of the transit method, making it easier to find smaller planets like Earth, as Michael Hippke of Sonneberg Observatory said:

Our new algorithm helps to draw a more realistic picture of the exoplanet population in space. This method constitutes a significant step forward, especially in the search for Earth-like planets.

All of the new planets were found in data from the K2 part of the Kepler mission. The K2 phase was initiated after the primary mission ended in 2013, after technical malfunctions with the telescope’s reaction wheels, which helped to keep Kepler stable for its observations of stars (K2 then ended in 2018). These researchers re-analyzed the 517 stars from K2 that were known to have at least one planet each.

The transit method looks for exoplanets as they pass in front of their stars. The new, more sensitive Transit Least-Squares algorithm can detect smaller planets like Earth. Image via NASA/SDO (Sun), MPS/René Heller.

So what are these new planets like?

Most of them, unfortunately, are not good candidates for life, orbiting their stars closer than any seen before, with temperatures ranging from over 212 degrees Fahrenheit (100 degrees Celsius) to 1,832 degrees Fahrenheit (1,000 degrees Celsius). One of them, however, EPIC 201238110.02, orbits within its star’s habitable zone, the region around a star where liquid water can exist. EPIC 201238110.02 is 1.87 times Earth’s diameter and 522 light-years away.

The first planet, K2-32e, orbits the star EPIC 205071984 and is the fourth known planet in that system. The other three planets are all Neptune-sized.

It is now expected that – using Transit Least-Squares – astronomers should be able to find at least another 100 Earth-sized planets in the data from the primary Kepler mission phase. This bodes well for discovering many more such worlds with other telescopes as well, such as NASA’s orbiting TESS satellite, the newest member of the planet-hunting family, which has picked up where Kepler left off.

The European Space Agency’s PLATO is another mission that will benefit from these findings with the new algorithm, according to Laurent Gizon, managing director at the Max Planck Institute for Solar System Research:

This new method is also particularly useful to prepare for the upcoming PLATO mission to be launched in 2026 by the European Space Agency.

The 18 new exoplanets were discovered in data from the Kepler Space Telescope, which ended its mission in late 2018. Image via NASA.

Future telescopes, both space and land-based, are expected to find thousands more exoplanets in the years ahead, including ones that are Earth-sized, like these 18 new ones. Some telescopes, such as NASA’s upcoming James Webb Space Telescope, will also be able to analyze the atmospheres of some of those distant worlds, looking for trace gases that may be a sign of life.

Bottom line: With another 18 Earth-sized exoplanets found hiding in Kepler data, astronomers continue to confirm that not only does this kind of rocky world exist elsewhere, but also that they are rather common. How many of them may turn out to be habitable for some kind of life is still unknown, but these discoveries are bringing us closer to finding the first evidence for life outside of our solar system.

Source: Transit least-squares survey – I. Discovery and validation of an Earth-sized planet in the four-planet system K2-32 near the 1:2:5:7 resonance

Source: Transit least-squares survey – II. Discovery and validation of 17 new sub- to super-Earth-sized planets in multi-planet systems from K2

Via Max Planck Institute for Solar System Research

from EarthSky http://bit.ly/2wovkiu

Size comparison with Earth, Neptune and the 18 newly discovered exoplanets. Wouldn’t it be grand to see surface details on these new worlds? Image via NASA/JPL (Neptune), NASA/NOAA/GSFC/Suomi NPP/VIIRS/Norman Kuring (Earth), MPS/René Heller.

Exoplanets about the same size as Earth can be some of the most difficult to detect, but their numbers are growing, and now scientists from the Max Planck Institute for Solar System Research, the Georg August University of Göttingen and the Sonneberg Observatory have added 18 more exoplanets to the ever-expanding list (as of May 1, 2019, there were 4,058 confirmed planets in 3,033 systems, with 658 systems having more than one planet). All 18 new exoplanets were found during a re-analysis of data from the highly effective Kepler Space Telescope planet-hunting mission, using a new, more sensitive search algorithm called Transit Least-Squares.

The first fruits of the new algorithm may be found in peer-reviewed findings published in the journal Astronomy & Astrophysics in two new papers, here and here. The first paper, focusing on exoplanet K2-32e, was published a few weeks ago, and the second paper regarding the other 17 exoplanets was published on May 21, 2019.

These newly-found worlds are some of the smallest detected so far. They range in size from only 69 percent of the diameter of Earth (EPIC 201497682.03, 831 light-years away) to just slightly more than twice as large as Earth. All of them were hiding in the Kepler data, and were not found in previous searches because the search algorithms were not sensitive enough. Like many other exoplanet hunters, Kepler used the transit method, where a planet passes in front of its star, as seen from our vantage point here on Earth. As the planet transits in front of the star, it blocks out a tiny amount of the light coming from the star, which can then be measured by astronomers. As René Heller of Max Planck Institute, first author of both papers, explained:

Standard search algorithms attempt to identify sudden drops in brightness. In reality, however, a stellar disk appears slightly darker at the edge than in the center. When a planet moves in front of a star, it therefore initially blocks less starlight than at the mid-time of the transit. The maximum dimming of the star occurs in the center of the transit just before the star becomes gradually brighter again.

Artist’s concept of Kepler-186f, the first Earth-sized exoplanet found orbiting in the habitable zone of its star. A growing number of such worlds have been found in recent years, including the 18 new exoplanets just announced. Image via NASA Ames/JPL-Caltech/T. Pyle.

As could be expected, larger planets are the easiest to detect, since they block out more light from their stars during a transit. The amount of light blocked by smaller planets can easily be missed, as it can be hard to distinguish from the natural brightness fluctuations of the star itself and the background noise that is part of these kinds of observations.

The new Transit Least-Squares algorithm improves the sensitivity of the transit method, making it easier to find smaller planets like Earth, as Michael Hippke of Sonneberg Observatory said:

Our new algorithm helps to draw a more realistic picture of the exoplanet population in space. This method constitutes a significant step forward, especially in the search for Earth-like planets.

All of the new planets were found in data from the K2 part of the Kepler mission. The K2 phase was initiated after the primary mission ended in 2013, after technical malfunctions with the telescope’s reaction wheels, which helped to keep Kepler stable for its observations of stars (K2 then ended in 2018). These researchers re-analyzed the 517 stars from K2 that were known to have at least one planet each.

The transit method looks for exoplanets as they pass in front of their stars. The new, more sensitive Transit Least-Squares algorithm can detect smaller planets like Earth. Image via NASA/SDO (Sun), MPS/René Heller.

So what are these new planets like?

Most of them, unfortunately, are not good candidates for life, orbiting their stars closer than any seen before, with temperatures ranging from over 212 degrees Fahrenheit (100 degrees Celsius) to 1,832 degrees Fahrenheit (1,000 degrees Celsius). One of them, however, EPIC 201238110.02, orbits within its star’s habitable zone, the region around a star where liquid water can exist. EPIC 201238110.02 is 1.87 times Earth’s diameter and 522 light-years away.

The first planet, K2-32e, orbits the star EPIC 205071984 and is the fourth known planet in that system. The other three planets are all Neptune-sized.

It is now expected that – using Transit Least-Squares – astronomers should be able to find at least another 100 Earth-sized planets in the data from the primary Kepler mission phase. This bodes well for discovering many more such worlds with other telescopes as well, such as NASA’s orbiting TESS satellite, the newest member of the planet-hunting family, which has picked up where Kepler left off.

The European Space Agency’s PLATO is another mission that will benefit from these findings with the new algorithm, according to Laurent Gizon, managing director at the Max Planck Institute for Solar System Research:

This new method is also particularly useful to prepare for the upcoming PLATO mission to be launched in 2026 by the European Space Agency.

The 18 new exoplanets were discovered in data from the Kepler Space Telescope, which ended its mission in late 2018. Image via NASA.

Future telescopes, both space and land-based, are expected to find thousands more exoplanets in the years ahead, including ones that are Earth-sized, like these 18 new ones. Some telescopes, such as NASA’s upcoming James Webb Space Telescope, will also be able to analyze the atmospheres of some of those distant worlds, looking for trace gases that may be a sign of life.

Bottom line: With another 18 Earth-sized exoplanets found hiding in Kepler data, astronomers continue to confirm that not only does this kind of rocky world exist elsewhere, but also that they are rather common. How many of them may turn out to be habitable for some kind of life is still unknown, but these discoveries are bringing us closer to finding the first evidence for life outside of our solar system.

Source: Transit least-squares survey – I. Discovery and validation of an Earth-sized planet in the four-planet system K2-32 near the 1:2:5:7 resonance

Source: Transit least-squares survey – II. Discovery and validation of 17 new sub- to super-Earth-sized planets in multi-planet systems from K2

Via Max Planck Institute for Solar System Research

from EarthSky http://bit.ly/2wovkiu

Deneb, tail of Cygnus the Swan

Tonight, look for Deneb, the brightest star in the constellation Cygnus the Swan. The night sky chart at the top of this post presents the view toward the northeast in mid-to-late evening during the month of May. It’s the view from mid-northern latitudes.

This star is part of not one but two striking star patterns. And it’s one of the most distant stars we can see with the eye alone, well over 1,000 light-years away.

Here is the Summer Triangle asterism – three bright stars in three different constellations – as photographed by EarthSky Facebook friend Susan Jensen in Odessa, Washington. Thank you, Susan!

Deneb is part of the Summer Triangle pattern. Deneb – along with the stars Vega and Altair – is part of the famous Summer Triangle asterism, which will be well up in the east in mid-evening next month. On these Northern Hemisphere late spring evenings, you might not be able to see the whole Summer Triangle until later at night. The star Altair will be the last of these three stars to rise. But you can see the bright star Deneb to the lower left of Vega, the Summer Triangle’s brightest star.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Deneb is also part of a smaller, cross-like pattern. Deneb is the brightest star in the constellation Cygnus the Swan. If you look at the cross-like pattern indicated on the chart at the top of this post, you might be able to imagine Deneb as the point marking the short tail of a long-necked swan flying toward the south. This is how early Arabian stargazers saw it. The name Deneb comes from the Arabic and means tail, and in skylore Deneb is often said to be the Tail of the Swan. The little star Albireo marks the Swan’s Head.

But there’s another way to see this pattern of stars that works equally well. In more modern skylore, this pattern is sometimes called the Northern Cross. It looks like a cross, right? If you prefer to see the Cross instead of the Swan, Deneb marks the head of the Cross.

Cross or Swan … this is a lovely pattern to pick out on the sky’s dome.

Astronomers know that Deneb is one of the most distant stars we can see with the eye alone. The exact distance to Deneb can only be estimated, with estimates ranging from about 1,425 light-years to perhaps as much as 7,000 light-years. At any of these estimated distances, Deneb is one of the farthest stars the unaided human eye can see. It is so far, that the light that reaches the Earth today started on its journey well more than 1,000 years ago.

More about Deneb: Very distant and very luminous

Bottom line: The star Deneb is part of the Summer Triangle asterism. And it’s part of the constellation Cygnus the Swan, which can also be seen as a Cross. Look for the star Deneb tonight! At well over 1,000 light-years away, it’s one of the most distant stars we can see with the eye alone.

A planisphere is a virtually indispensable tool for beginning stargazers. Order your EarthSky planisphere from our store.

from EarthSky http://bit.ly/2JExrHH

Tonight, look for Deneb, the brightest star in the constellation Cygnus the Swan. The night sky chart at the top of this post presents the view toward the northeast in mid-to-late evening during the month of May. It’s the view from mid-northern latitudes.

This star is part of not one but two striking star patterns. And it’s one of the most distant stars we can see with the eye alone, well over 1,000 light-years away.

Here is the Summer Triangle asterism – three bright stars in three different constellations – as photographed by EarthSky Facebook friend Susan Jensen in Odessa, Washington. Thank you, Susan!

Deneb is part of the Summer Triangle pattern. Deneb – along with the stars Vega and Altair – is part of the famous Summer Triangle asterism, which will be well up in the east in mid-evening next month. On these Northern Hemisphere late spring evenings, you might not be able to see the whole Summer Triangle until later at night. The star Altair will be the last of these three stars to rise. But you can see the bright star Deneb to the lower left of Vega, the Summer Triangle’s brightest star.

Enjoying EarthSky so far? Sign up for our free daily newsletter today!

Deneb is also part of a smaller, cross-like pattern. Deneb is the brightest star in the constellation Cygnus the Swan. If you look at the cross-like pattern indicated on the chart at the top of this post, you might be able to imagine Deneb as the point marking the short tail of a long-necked swan flying toward the south. This is how early Arabian stargazers saw it. The name Deneb comes from the Arabic and means tail, and in skylore Deneb is often said to be the Tail of the Swan. The little star Albireo marks the Swan’s Head.

But there’s another way to see this pattern of stars that works equally well. In more modern skylore, this pattern is sometimes called the Northern Cross. It looks like a cross, right? If you prefer to see the Cross instead of the Swan, Deneb marks the head of the Cross.

Cross or Swan … this is a lovely pattern to pick out on the sky’s dome.

Astronomers know that Deneb is one of the most distant stars we can see with the eye alone. The exact distance to Deneb can only be estimated, with estimates ranging from about 1,425 light-years to perhaps as much as 7,000 light-years. At any of these estimated distances, Deneb is one of the farthest stars the unaided human eye can see. It is so far, that the light that reaches the Earth today started on its journey well more than 1,000 years ago.

More about Deneb: Very distant and very luminous

Bottom line: The star Deneb is part of the Summer Triangle asterism. And it’s part of the constellation Cygnus the Swan, which can also be seen as a Cross. Look for the star Deneb tonight! At well over 1,000 light-years away, it’s one of the most distant stars we can see with the eye alone.

A planisphere is a virtually indispensable tool for beginning stargazers. Order your EarthSky planisphere from our store.

from EarthSky http://bit.ly/2JExrHH

Beleaguered journalism interests seek to aid ailing planet

This is a re-post from Yale Climate Connections by Bud Ward

Let’s buy for a moment the well-traveled viewpoint that the news media like nothing better than a good crisis. Nothing like a crisis, and better yet two, to kick reporters’ and editors’, let alone media bean counters’, adrenaline into overdrive. Bring on the banner headlines, the grit and joy of covering someone else’s disasters up-close and personal, perhaps even a greater shot at one of journalism’s more glamorous prizes or awards.

But what, one might ask, when the crisis is not someone else’s, but rather a crisis in the house of journalism itself? As with the current decades-old and decades-more-to-come demise of the subscriber- and advertiser-paid business model? What if, one well might wonder, the crisis is in journalism itself?

Commentary

And to compound the dilemma at hand, what if the crisis in journalism comes during an equally, and by all accounts even more serious (truly existential?) confounding crisis? As in misery loves company.

Take the climate change crisis as Exhibit A.

As luck would have it – bad luck, that is – the climate change crisis as we understand it, and as we don’t yet fully understand it, has been occurring and will continue to occur during a time of crisis for responsible journalism. Oh darn.

Journalism gurus pretty much accept that the ongoing crises of change surrounding and overwhelming many news enterprises will go on for a number of decades before, one hopes, we can all adapt to where it ends up. We can be pretty certain that our kids, and also theirs, will be dealing with this snowballing news/information dilemma for years, probably decades, to come.

The same, of course, applies to what many experts now feel can only fairly be characterized as a “climate crisis.” Again, as with journalism, it’s a crisis of our own making.

It’s not like there aren’t serious efforts to help mitigate the long-term harm, to avoid the worst possible impacts. And we can take comfort that that applies, at least for now, to both journalism and to climate change.

Climate crisis … meet journalism crisis

So it’s into this double-edged conundrum that enters the proverbial knight in shining armor. It comes in the form of a new consortium of journalism interests with the specific purpose of vastly improving media coverage of the climate crisis. No small challenge, that.

For into this muddle comes the storied Columbia Journalism Review, operating from within the hallowed halls of perhaps the world’s foremost academic shrine to journalism excellence, and a supporting crew of committed journalism organizations.

United behind the hashtag #CoveringClimateNow, this foundation-funded effort has in mind nothing less than what CJR Editor Kyle Pope has called “an unprecedented week-long organization of the media to focus coverage on climate change,” And that’s just one component of the overall plan, one that on its own could make herding cats seem a walk in the park.

With a $1 million grant from the Schumann Foundation and its veteran journalist and author Bill Moyers, the new initiative met at Columbia in late April amid an admiring crowd of like-minded media representatives and concerned climate activists. Co-sponsored in part by The Nation magazine and its veteran environment correspondent Mark Hertsgaard, the session featured speakers and panelists who presented a number of salient observations about the nuts and bolts – and also about the heart and conscience and the blood and guts – of journalism in this current era, some no doubt more realistic than others:

• Author and activist Bill McKibben: “It’s not the job of journalists to see that people get upset, but the news is upsetting.”
• Margaret Sullivan of the Washington Post: It’s fine for news media to be advocates for press rights. Does it follow that they can also be advocates for a “healthy planet”?
• Book author, opinion columnist, and self-identified provocateur and activist Naomi Klein: “It is impossible to be apathetic about the end of the world.” Scared? Yes, but not apathetic. Klein also suggested a need for a disinvestment movement on the part of news media: Ban fossil fuel advertisements, as they outweigh the amount of news coverage on greenhouse gases and fossil fuels.
• Book author and journalist Hertsgaard discussed plans for “a journalist’s playbook for a 1.5 C [degree] world”
• Environmental advocate and campaigner David Fenton said that for the “three major networks – climate change is ‘missing in action’ … it doesn’t exist … a giant act of moral cowardice” based on networks’ fear of right-wing retribution.
• Author and TV veteran Moyers, long a top official with the Schumann Foundation and bearer of the $1 million Schumann check: quoted David Attenborough as expressing climate concerns and resulting prospects for “the collapse of civilization and the extinction of much of the natural world.”

Some preliminary ideas

As part of its launch, the media consortium, which included The Guardian of the U.K., published a Hertsgaard and Pope essay in The Nation entitled “The media are complacent while the world burns.”

In that piece, the two authors put forward a series of “preliminary suggestions” under such sub-headlines as:

• Follow the leaders, “emulate outlets that are already covering climate change well.”
• Don’t blame the audience and listen to the kids.
• Establish a diverse climate desk, but don’t silo climate coverage.
• Learn the science.
• Don’t internalize the spin.
• Lose the Beltway mindset.
• Help the Heartland.
• Cover the solutions.
• Don’t be afraid to point figures.

Their provocative and entreaty-filled ideas amount to the proverbial clarion call to action, in this case for the enfeebled news media to come to the aid of an endangered and in many ways politically immobilized planet, ours.

Hertsgaard and Pope conclude their piece by writing: “If American journalism doesn’t get the climate story right – and soon – no other story will matter. The news media’s past climate failures can be redeemed only by an immediate shift to more high-profile, inclusive, and fearless coverage.”

Who among sentient and caring human beings, one might seriously ask, could fault the effort? Who also, one might wonder, might be tempted to ask: What could possibly go wrong?

Sure. Plenty, one might reasonably think. But as they say, “any ship in a storm,” and this still-emerging initiative seems as seaworthy as any other yet proposed to take on the double-jeopardy challenges of a weakened news media in a warming climate.

See related story: CJR’s covering climate change event proposes better journalism for a better climate

from Skeptical Science http://bit.ly/2XaqpNU

This is a re-post from Yale Climate Connections by Bud Ward

Let’s buy for a moment the well-traveled viewpoint that the news media like nothing better than a good crisis. Nothing like a crisis, and better yet two, to kick reporters’ and editors’, let alone media bean counters’, adrenaline into overdrive. Bring on the banner headlines, the grit and joy of covering someone else’s disasters up-close and personal, perhaps even a greater shot at one of journalism’s more glamorous prizes or awards.

But what, one might ask, when the crisis is not someone else’s, but rather a crisis in the house of journalism itself? As with the current decades-old and decades-more-to-come demise of the subscriber- and advertiser-paid business model? What if, one well might wonder, the crisis is in journalism itself?

Commentary

And to compound the dilemma at hand, what if the crisis in journalism comes during an equally, and by all accounts even more serious (truly existential?) confounding crisis? As in misery loves company.

Take the climate change crisis as Exhibit A.

As luck would have it – bad luck, that is – the climate change crisis as we understand it, and as we don’t yet fully understand it, has been occurring and will continue to occur during a time of crisis for responsible journalism. Oh darn.

Journalism gurus pretty much accept that the ongoing crises of change surrounding and overwhelming many news enterprises will go on for a number of decades before, one hopes, we can all adapt to where it ends up. We can be pretty certain that our kids, and also theirs, will be dealing with this snowballing news/information dilemma for years, probably decades, to come.

The same, of course, applies to what many experts now feel can only fairly be characterized as a “climate crisis.” Again, as with journalism, it’s a crisis of our own making.

It’s not like there aren’t serious efforts to help mitigate the long-term harm, to avoid the worst possible impacts. And we can take comfort that that applies, at least for now, to both journalism and to climate change.

Climate crisis … meet journalism crisis

So it’s into this double-edged conundrum that enters the proverbial knight in shining armor. It comes in the form of a new consortium of journalism interests with the specific purpose of vastly improving media coverage of the climate crisis. No small challenge, that.

For into this muddle comes the storied Columbia Journalism Review, operating from within the hallowed halls of perhaps the world’s foremost academic shrine to journalism excellence, and a supporting crew of committed journalism organizations.

United behind the hashtag #CoveringClimateNow, this foundation-funded effort has in mind nothing less than what CJR Editor Kyle Pope has called “an unprecedented week-long organization of the media to focus coverage on climate change,” And that’s just one component of the overall plan, one that on its own could make herding cats seem a walk in the park.

With a $1 million grant from the Schumann Foundation and its veteran journalist and author Bill Moyers, the new initiative met at Columbia in late April amid an admiring crowd of like-minded media representatives and concerned climate activists. Co-sponsored in part by The Nation magazine and its veteran environment correspondent Mark Hertsgaard, the session featured speakers and panelists who presented a number of salient observations about the nuts and bolts – and also about the heart and conscience and the blood and guts – of journalism in this current era, some no doubt more realistic than others:

• Author and activist Bill McKibben: “It’s not the job of journalists to see that people get upset, but the news is upsetting.”
• Margaret Sullivan of the Washington Post: It’s fine for news media to be advocates for press rights. Does it follow that they can also be advocates for a “healthy planet”?
• Book author, opinion columnist, and self-identified provocateur and activist Naomi Klein: “It is impossible to be apathetic about the end of the world.” Scared? Yes, but not apathetic. Klein also suggested a need for a disinvestment movement on the part of news media: Ban fossil fuel advertisements, as they outweigh the amount of news coverage on greenhouse gases and fossil fuels.
• Book author and journalist Hertsgaard discussed plans for “a journalist’s playbook for a 1.5 C [degree] world”
• Environmental advocate and campaigner David Fenton said that for the “three major networks – climate change is ‘missing in action’ … it doesn’t exist … a giant act of moral cowardice” based on networks’ fear of right-wing retribution.
• Author and TV veteran Moyers, long a top official with the Schumann Foundation and bearer of the $1 million Schumann check: quoted David Attenborough as expressing climate concerns and resulting prospects for “the collapse of civilization and the extinction of much of the natural world.”

Some preliminary ideas

As part of its launch, the media consortium, which included The Guardian of the U.K., published a Hertsgaard and Pope essay in The Nation entitled “The media are complacent while the world burns.”

In that piece, the two authors put forward a series of “preliminary suggestions” under such sub-headlines as:

• Follow the leaders, “emulate outlets that are already covering climate change well.”
• Don’t blame the audience and listen to the kids.
• Establish a diverse climate desk, but don’t silo climate coverage.
• Learn the science.
• Don’t internalize the spin.
• Lose the Beltway mindset.
• Help the Heartland.
• Cover the solutions.
• Don’t be afraid to point figures.

Their provocative and entreaty-filled ideas amount to the proverbial clarion call to action, in this case for the enfeebled news media to come to the aid of an endangered and in many ways politically immobilized planet, ours.

Hertsgaard and Pope conclude their piece by writing: “If American journalism doesn’t get the climate story right – and soon – no other story will matter. The news media’s past climate failures can be redeemed only by an immediate shift to more high-profile, inclusive, and fearless coverage.”

Who among sentient and caring human beings, one might seriously ask, could fault the effort? Who also, one might wonder, might be tempted to ask: What could possibly go wrong?

Sure. Plenty, one might reasonably think. But as they say, “any ship in a storm,” and this still-emerging initiative seems as seaworthy as any other yet proposed to take on the double-jeopardy challenges of a weakened news media in a warming climate.

See related story: CJR’s covering climate change event proposes better journalism for a better climate

from Skeptical Science http://bit.ly/2XaqpNU

Tiny dips in star brightnesses reveal 3 exocomets

View larger. | Parts of the TESS light curve of Beta Pictoris showing the 3 dimming events caused by the exocomets. Image via Sebastian Zieba/Konstanze Zwintz/University of Innsbruck.

You’ve heard of exoplanets, or planets orbiting distant stars. Astronomers have also detected some exocomets, or comets orbiting faraway stars, too. When you think of it, exocomet detections are an amazing accomplishment! In contrast to planets, which are relatively solid and thousands of miles wide, the nuclei, or cores, of comets are only a few miles wide. However, when they come near their stars, comets develop long (if tenuous) tails that can stretch millions of miles. The first exocomets were detected in 1987 around the famous star Beta Pictoris, 63 light-years away, a very young A-type main-sequence star. Now three more exocomets have been discovered for Beta Pictoris by European and U.K. astronomers. They used data from TESS – NASA’s newest space-based planet-hunter, launched in April 2018 – to make the find, making these the first exocomets for TESS.

Sebastian Zieba (@CyberZieba on Twitter) and Konstanze Zwintz, both at University of Innsbruck in Austria – together with Matthew Kenworthy from Leiden University in the Netherlands and Grant Kennedy from the University of Warwick in the U.K. – made the discovery. Their work has been accepted for publication in the peer-reviewed journal Astronomy and Astrophysics. Find it online here.

TESS stands for Transiting Exoplanet Survey Satellite. As the name suggests, it searches for exoplanets (and exocomets) that transit, or cross in front of, their stars as viewed from Earth. When an object transits in front of its star, there is a tiny dip in the light received from the star. These dips reveal exoplanets, or, in this case, exocomets. As these astronomers pointed out in a statement:

The recognition of signals from much smaller exocomets compared to planets requires the analysis of a precise light curve, which can now be obtained using the technical sophistication of the new space telescope.

TESS finds planets and comets via precise measurements of the brightnesses of stars. When a planet or comet crosses in front of its star, it causes a tiny dip in the star’s light, which can be observed. Animation via NASA: How TESS Looks for Exoplanets.

Sebastian Zieba is a Master’s student in the team of Konstanze Zwintz at the at the University of Innsbruck. Zieba discovered the signal of the exocomets when he investigated the TESS light curve of Beta Pictoris in March this year. Zieba and Zwintz explained:

The data showed a significant decrease in the intensity of the light of the observed star. These variations due to darkening by an object in the star’s orbit can clearly be related to a comet.

Three similar exocomet systems have recently been found around three other stars during data analysis by NASA’s Kepler mission. The researchers suggest that exocomets are more likely to be found around young stars. Zwintz said:

The space telescope Kepler concentrated on older stars similar to the sun in a relatively small area in the sky. TESS, on the other hand, observes stars all over the sky, including young stars. We therefore expect further discoveries of this kind in the future.

Grant Kennedy assisted with the modeling and interpretation of the data. He said:

This discovery is really important for the science of extrasolar comets for several reasons. Beta Pictoris had been thought to host exocomets for three decades from a different technique, and the TESS data provide long overdue and independent evidence for their existence. Our next aim is to find similar signatures around other stars, and this discovery shows that TESS is up to the task.

View larger. | Artist’s concept of 3 exocomets in the very young planetary system around the star Beta Pictoris. Image via Michaela Pink/University of Innsbruck.

The young and very bright star Beta Pictoris is a famous star for many reasons, these astronomers said. Zwintz explained:

Already in the 1980s, investigations of Beta Pictoris provided convincing evidence for planetary systems around stars other than our sun – a decade before exoplanets were even discovered for the first time. In addition, there was already indirect evidence for comets at that time based on the characteristic signature of evaporating gas coming off them.

At about 23 million years old, Beta Pictoris is a relatively young star.

The discovery of exocomets around Beta Pictoris was predicted in 1999 in a paper by the astrophysicists Alain Lecavelier des Etangs, Alfred Vidal-Madjar and Roger Ferlet. Zieba and Zwintz said:

Together with our colleagues from Leiden and Warwick, we are pleased to have finally confirmed this theory.

They said they expect to discover many more comets and asteroids in distant solar systems, and they said they want to investigate the composition of exocomets, for example regarding their water content. Zwintz pointed out:

What we are seeing is not the comet nucleus itself, but the material blown off the comet and trailing behind it. So the TESS data do not tell us how big the comets were, since the extent of the dust tail could be very big and not very dense, or less big and more dense. Both situations would give the same light curve.

View larger. | Artist’s concept of the Transiting Exoplanet Survey Satellite (TESS) in orbit around Earth. Image via NASA’s Goddard Space Flight Center/University of Innsbruck.

Bottom line: Astronomers have detected the first 3 exocomets found in data gathered by TESS, NASA’s newest planet-hunter. The comets orbit the famous star Beta Pictoris.

Source: A transiting exocomet detected in broadband light by TESS in the Beta Pictoris system

Via University of Innsbruck

from EarthSky http://bit.ly/2whztEY

View larger. | Parts of the TESS light curve of Beta Pictoris showing the 3 dimming events caused by the exocomets. Image via Sebastian Zieba/Konstanze Zwintz/University of Innsbruck.

You’ve heard of exoplanets, or planets orbiting distant stars. Astronomers have also detected some exocomets, or comets orbiting faraway stars, too. When you think of it, exocomet detections are an amazing accomplishment! In contrast to planets, which are relatively solid and thousands of miles wide, the nuclei, or cores, of comets are only a few miles wide. However, when they come near their stars, comets develop long (if tenuous) tails that can stretch millions of miles. The first exocomets were detected in 1987 around the famous star Beta Pictoris, 63 light-years away, a very young A-type main-sequence star. Now three more exocomets have been discovered for Beta Pictoris by European and U.K. astronomers. They used data from TESS – NASA’s newest space-based planet-hunter, launched in April 2018 – to make the find, making these the first exocomets for TESS.

Sebastian Zieba (@CyberZieba on Twitter) and Konstanze Zwintz, both at University of Innsbruck in Austria – together with Matthew Kenworthy from Leiden University in the Netherlands and Grant Kennedy from the University of Warwick in the U.K. – made the discovery. Their work has been accepted for publication in the peer-reviewed journal Astronomy and Astrophysics. Find it online here.

TESS stands for Transiting Exoplanet Survey Satellite. As the name suggests, it searches for exoplanets (and exocomets) that transit, or cross in front of, their stars as viewed from Earth. When an object transits in front of its star, there is a tiny dip in the light received from the star. These dips reveal exoplanets, or, in this case, exocomets. As these astronomers pointed out in a statement:

The recognition of signals from much smaller exocomets compared to planets requires the analysis of a precise light curve, which can now be obtained using the technical sophistication of the new space telescope.

TESS finds planets and comets via precise measurements of the brightnesses of stars. When a planet or comet crosses in front of its star, it causes a tiny dip in the star’s light, which can be observed. Animation via NASA: How TESS Looks for Exoplanets.

Sebastian Zieba is a Master’s student in the team of Konstanze Zwintz at the at the University of Innsbruck. Zieba discovered the signal of the exocomets when he investigated the TESS light curve of Beta Pictoris in March this year. Zieba and Zwintz explained:

The data showed a significant decrease in the intensity of the light of the observed star. These variations due to darkening by an object in the star’s orbit can clearly be related to a comet.

Three similar exocomet systems have recently been found around three other stars during data analysis by NASA’s Kepler mission. The researchers suggest that exocomets are more likely to be found around young stars. Zwintz said:

The space telescope Kepler concentrated on older stars similar to the sun in a relatively small area in the sky. TESS, on the other hand, observes stars all over the sky, including young stars. We therefore expect further discoveries of this kind in the future.

Grant Kennedy assisted with the modeling and interpretation of the data. He said:

This discovery is really important for the science of extrasolar comets for several reasons. Beta Pictoris had been thought to host exocomets for three decades from a different technique, and the TESS data provide long overdue and independent evidence for their existence. Our next aim is to find similar signatures around other stars, and this discovery shows that TESS is up to the task.

View larger. | Artist’s concept of 3 exocomets in the very young planetary system around the star Beta Pictoris. Image via Michaela Pink/University of Innsbruck.

The young and very bright star Beta Pictoris is a famous star for many reasons, these astronomers said. Zwintz explained:

Already in the 1980s, investigations of Beta Pictoris provided convincing evidence for planetary systems around stars other than our sun – a decade before exoplanets were even discovered for the first time. In addition, there was already indirect evidence for comets at that time based on the characteristic signature of evaporating gas coming off them.

At about 23 million years old, Beta Pictoris is a relatively young star.

The discovery of exocomets around Beta Pictoris was predicted in 1999 in a paper by the astrophysicists Alain Lecavelier des Etangs, Alfred Vidal-Madjar and Roger Ferlet. Zieba and Zwintz said:

Together with our colleagues from Leiden and Warwick, we are pleased to have finally confirmed this theory.

They said they expect to discover many more comets and asteroids in distant solar systems, and they said they want to investigate the composition of exocomets, for example regarding their water content. Zwintz pointed out:

What we are seeing is not the comet nucleus itself, but the material blown off the comet and trailing behind it. So the TESS data do not tell us how big the comets were, since the extent of the dust tail could be very big and not very dense, or less big and more dense. Both situations would give the same light curve.

View larger. | Artist’s concept of the Transiting Exoplanet Survey Satellite (TESS) in orbit around Earth. Image via NASA’s Goddard Space Flight Center/University of Innsbruck.

Bottom line: Astronomers have detected the first 3 exocomets found in data gathered by TESS, NASA’s newest planet-hunter. The comets orbit the famous star Beta Pictoris.

Source: A transiting exocomet detected in broadband light by TESS in the Beta Pictoris system

Via University of Innsbruck

from EarthSky http://bit.ly/2whztEY

Stolen comets and free-floating objects

I love the video above. It shows what happens when two young stars – still surrounded by their disks of planetesimals, or planet-building blocks – encounter each other. It’s based on recent computer simulations, part of a newly published study by astrophysicists at the University of Zurich, describing how our solar system likely contains comets stolen from a star that swept near our sun 4.5 billion years ago. Stars like our sun are born in clusters. Our sun is thought to be about 4.5 billion years old. So we’re talking about the very young sun here, newly emerged from the cloud of gas and dust that created it and its sister stars. The new study says that, when two young stars meet, their encircling disks mix it up, literally. In particular, the outer planetesimals of the smaller star are heavily disrupted by its higher-mass sibling. Some planetesimals – chunks of rocky or icy material – switch from one star system to the other. They are “stolen,” in other words.

And some planetesimals leave both star systems behind entirely. Tom Hands, who led the new study, explained:

[The encounter] causes a bunch of planetesimals to be ejected, flying away to become things like ‘Oumuamua [the small interstellar object that recently swept near our sun]. I was surprised by the number of ‘Oumuamua-like free-floating objects that can be generated in an environment like this on a relatively short time-scale.

‘Oumuamua is a now-famous object among astronomers, who noticed it and began tracking its movement through our solar system in 2017. Though many free-floating objects are thought to exist, ‘Oumuamua is the only small interstellar object seen moving in our solar system so far. It’s not attached to our sun, or any star. That’s how it received its name, which is Hawaiian for “a messenger from afar arriving first.” Astronomers don’t know where ‘Oumuamua came from, exactly. Speaking about the new study, Tom Hands and his colleagues’ statement said:

… it is clear that free-floating planetesimals, comets and asteroids should be ubiquitous in the galaxy.

This diagram shows the path of the interstellar object ‘Oumuamua – the first known interstellar object to pass through our solar system – as it was sweeping toward our sun in late 2017, rounded the sun, and then began moving outward again. ‘Oumuamua passed the distance of Jupiter’s orbit in May 2018. It passed the distance of Saturn’s orbit in January 2019. It will reach a distance corresponding to Neptune’s orbit in 2022, according to some studies. Image via SpaceTelescope.org.

‘Oumuamua made headlines after it was discovered in October 2017. Many theories have been suggested to explain its origin, including the possibility of its being an alien spacecraft.

Researchers at the University of Zürich used a large computer simulations to show how ‘Oumuamua-style objects can be set on their solitary paths through space. They calculated what happens when multiple young stars are born together in a stellar cluster, much as our sun is thought to have been 4.5 billion years ago. Most of what astronomers call planetesimals – the building blocks of planets – ultimately do become planets, comets and asteroids while the stars are still in their infancy. But not all do. Tom Hands commented:

Coming into close contact with other stars can have a profound effect on these planetary systems.

I was also surprised by the ease with which stars can steal material from their stellar siblings at a young age.

Artist’s concept of the cigar-shaped interstellar object ‘Oumuamua. Image via ESA/Hubble, NASA, ESO, M. Kornmesser, NCCR PlanetS.

Even now, our sun might retain alien comets stolen from another star in these early phases. Hands said:

Even if alien material is really there, there likely isn’t much of it. But we might be able to detect it based on the strange orbits this stuff could be on.

Hands said his research has relevance to the ongoing search for a 9th planet in our solar system, which is based on an odd alignment of orbits of small objects in the outer solar system. He said the results of his study suggest that a large, unseen 9th planet isn’t the only plausible explanation for this observed alignment. Hands commented:

People should keep an open mind when considering how these things might have ended up on the orbits they are on.

Finally, he commented:

This is the first time we have been able to get a feeling for how the cluster environment could affect our Kuiper belt, or similar structures in exoplanetary systems

And I don’t think he’s boasting there. It seems like novel research to me. Forty-plus years ago, when I started writing about astronomy, we’d sometimes hear astronomers say that comets in the Oort Cloud could be dislodged by “passing stars” and thereby be sent hurtling in toward our sun. I always wondered which passing stars, and when, and what went on there? To my knowledge, this study doesn’t relate specifically to Oort Cloud comets; it does talk about objects in the Kuiper Belt, though, which are also in our solar system’s outer reaches, at a lesser distance from our sun. Both Oort Cloud and Kuiper Belt material would surely be affected by an encounter with another star 4.5 billion years ago. It’s great to have an actual simulation, at last, that provides concrete images of this long-discussed encounter.

And, by the way – on an entirely different subject – I found a second super cool video at Tom Hands’ website, also based on his computer simulations. You might enjoy it, too, so I posted it below. It’s an exoplanet visualization, based on data from the Open Exoplanet Catalog. He described the video below as:

… a flyby of all known exoplanets around single stars. The systems are ordered according to the largest semi-major axis (planet-star separation) within each of them, from largest to smallest. The systems that you fly past first contain planets which takes hundreds or even thousands of years to orbit their stars, whilst by the end they take mere hours or days. Designed to give the viewer an overview of the current distribution of exoplanets.

Amazing, right? Thanks, Tom!

You’ll find Tom Hands on Twitter as @TomHandsPhysics.

Bottom line: A new study from Tom Hands and colleagues at the University of Zurich suggests our solar system contains comets stolen from another star 4.5 billion years ago. The interstellar visitor ‘Oumuamua might be an example of an object dislodged from its original solar system in that way. According to this study, there might be many free-floating objects like ‘Oumuamua in our galaxy.

Source: The fate of planetesimal discs in young open clusters: implications for 1I/’Oumuamua, the Kuiper belt, the Oort cloud and more

Via NCCR PlanetS

from EarthSky http://bit.ly/2EBDhFM

I love the video above. It shows what happens when two young stars – still surrounded by their disks of planetesimals, or planet-building blocks – encounter each other. It’s based on recent computer simulations, part of a newly published study by astrophysicists at the University of Zurich, describing how our solar system likely contains comets stolen from a star that swept near our sun 4.5 billion years ago. Stars like our sun are born in clusters. Our sun is thought to be about 4.5 billion years old. So we’re talking about the very young sun here, newly emerged from the cloud of gas and dust that created it and its sister stars. The new study says that, when two young stars meet, their encircling disks mix it up, literally. In particular, the outer planetesimals of the smaller star are heavily disrupted by its higher-mass sibling. Some planetesimals – chunks of rocky or icy material – switch from one star system to the other. They are “stolen,” in other words.

And some planetesimals leave both star systems behind entirely. Tom Hands, who led the new study, explained:

[The encounter] causes a bunch of planetesimals to be ejected, flying away to become things like ‘Oumuamua [the small interstellar object that recently swept near our sun]. I was surprised by the number of ‘Oumuamua-like free-floating objects that can be generated in an environment like this on a relatively short time-scale.

‘Oumuamua is a now-famous object among astronomers, who noticed it and began tracking its movement through our solar system in 2017. Though many free-floating objects are thought to exist, ‘Oumuamua is the only small interstellar object seen moving in our solar system so far. It’s not attached to our sun, or any star. That’s how it received its name, which is Hawaiian for “a messenger from afar arriving first.” Astronomers don’t know where ‘Oumuamua came from, exactly. Speaking about the new study, Tom Hands and his colleagues’ statement said:

… it is clear that free-floating planetesimals, comets and asteroids should be ubiquitous in the galaxy.

This diagram shows the path of the interstellar object ‘Oumuamua – the first known interstellar object to pass through our solar system – as it was sweeping toward our sun in late 2017, rounded the sun, and then began moving outward again. ‘Oumuamua passed the distance of Jupiter’s orbit in May 2018. It passed the distance of Saturn’s orbit in January 2019. It will reach a distance corresponding to Neptune’s orbit in 2022, according to some studies. Image via SpaceTelescope.org.

‘Oumuamua made headlines after it was discovered in October 2017. Many theories have been suggested to explain its origin, including the possibility of its being an alien spacecraft.

Researchers at the University of Zürich used a large computer simulations to show how ‘Oumuamua-style objects can be set on their solitary paths through space. They calculated what happens when multiple young stars are born together in a stellar cluster, much as our sun is thought to have been 4.5 billion years ago. Most of what astronomers call planetesimals – the building blocks of planets – ultimately do become planets, comets and asteroids while the stars are still in their infancy. But not all do. Tom Hands commented:

Coming into close contact with other stars can have a profound effect on these planetary systems.

I was also surprised by the ease with which stars can steal material from their stellar siblings at a young age.

Artist’s concept of the cigar-shaped interstellar object ‘Oumuamua. Image via ESA/Hubble, NASA, ESO, M. Kornmesser, NCCR PlanetS.

Even now, our sun might retain alien comets stolen from another star in these early phases. Hands said:

Even if alien material is really there, there likely isn’t much of it. But we might be able to detect it based on the strange orbits this stuff could be on.

Hands said his research has relevance to the ongoing search for a 9th planet in our solar system, which is based on an odd alignment of orbits of small objects in the outer solar system. He said the results of his study suggest that a large, unseen 9th planet isn’t the only plausible explanation for this observed alignment. Hands commented:

People should keep an open mind when considering how these things might have ended up on the orbits they are on.

Finally, he commented:

This is the first time we have been able to get a feeling for how the cluster environment could affect our Kuiper belt, or similar structures in exoplanetary systems

And I don’t think he’s boasting there. It seems like novel research to me. Forty-plus years ago, when I started writing about astronomy, we’d sometimes hear astronomers say that comets in the Oort Cloud could be dislodged by “passing stars” and thereby be sent hurtling in toward our sun. I always wondered which passing stars, and when, and what went on there? To my knowledge, this study doesn’t relate specifically to Oort Cloud comets; it does talk about objects in the Kuiper Belt, though, which are also in our solar system’s outer reaches, at a lesser distance from our sun. Both Oort Cloud and Kuiper Belt material would surely be affected by an encounter with another star 4.5 billion years ago. It’s great to have an actual simulation, at last, that provides concrete images of this long-discussed encounter.

And, by the way – on an entirely different subject – I found a second super cool video at Tom Hands’ website, also based on his computer simulations. You might enjoy it, too, so I posted it below. It’s an exoplanet visualization, based on data from the Open Exoplanet Catalog. He described the video below as:

… a flyby of all known exoplanets around single stars. The systems are ordered according to the largest semi-major axis (planet-star separation) within each of them, from largest to smallest. The systems that you fly past first contain planets which takes hundreds or even thousands of years to orbit their stars, whilst by the end they take mere hours or days. Designed to give the viewer an overview of the current distribution of exoplanets.

Amazing, right? Thanks, Tom!

You’ll find Tom Hands on Twitter as @TomHandsPhysics.

Bottom line: A new study from Tom Hands and colleagues at the University of Zurich suggests our solar system contains comets stolen from another star 4.5 billion years ago. The interstellar visitor ‘Oumuamua might be an example of an object dislodged from its original solar system in that way. According to this study, there might be many free-floating objects like ‘Oumuamua in our galaxy.

Source: The fate of planetesimal discs in young open clusters: implications for 1I/’Oumuamua, the Kuiper belt, the Oort cloud and more

Via NCCR PlanetS

from EarthSky http://bit.ly/2EBDhFM

Okinawa sunset

May 24, 2019. Image via Beverly Fish.

from EarthSky http://bit.ly/2QqwqUf

May 24, 2019. Image via Beverly Fish.

from EarthSky http://bit.ly/2QqwqUf