Space News/UFO's Etc...(Discussion/Pics/Vids)

[ilan]

This Week’s Sky at a Glance, September 23 – October 1
Alan MacRobert, Sky & Telescope | September 23, 2016

A bit late, but better than never. - Ilan

In the southwest at dusk, Saturn and Antares continue to pull farther away to the right of Mars. Summer ended yesterday, so this is a good time to declare that the triangle they make, the nightly celestial emblem of Summer 2016, is breaking up and losing its identity.

Friday, September 23

• The starry W of Cassiopeia stands high in the northeast after dark. The right-hand side of the W (the brightest side) is tilted up.

Look along the second segment of the W counting down from the top. Notice the dim naked-eye stars along that segment (not counting its two ends). The one on the right is Eta Cassiopeiae, magnitude 3.4, a Sun-like star just 19 light-years away with an orange-dwarf companion — a lovely binary in a telescope.

The "one" on the left, fainter, is a wide naked-eye pair: Upsilon1 and Upsilon2 Cassiopeiae, 0.3° apart. They're orange giants unrelated to each other, 200 and 400 light-years from us.

• Last-quarter Moon (exact at 5:56 a.m. Eastern Daylight Time on this date). The Moon rises around midnight or 1 a.m. on the morning of Saturday the 24th. Once it's fairly well up you'll see that it's in Gemini, with Castor and Pollux to its left. Orion is much farther to its right.

• Algol is at its minimum light, magnitude 3.4 instead of its usual 2.1, for about two hours centered on 11:19 p.m. EDT. Info and comparison-star chart.

Saturday, September 24

• This is the time of year when the rich Cygnus Milky Way crosses the zenith in the hour after nightfall is complete (for skywatchers at mid-northern latitudes). The Milky Way rises straight up from the southwest horizon, passed overhead, and runs straight down to the northeast.

Sunday, September 25

• About a half hour after your local sunset time, look for Venus very low in the west-southwest through the twilight. It's on its way to a grand apparition as the "Evening Star" high in the southwest this winter.

Monday, September 26

• Arcturus shines in the west these evenings as twilight fades out. Equally-bright Capella (they're both magnitude 0) is barely rising in the north-northeast, depending on your latitude; the farther north you are, the higher it will be. Late in the evening, Arcturus and Capella shine at the same height in their respective compass directions. When will this happen? It depends on both your latitude and longitude.
Moon, Regulus, and Mercury at dawn, Sept. 27-29, 2016

• Early Tuesday morning the 27th, the waning crescent Moon is about 6° upper right of Regulus (for North America), as shown at right. Look 17° below or lower right of Regulus for Mercury.

As dawn brightens in the east, the crescent Moon wanes and steps lower past Regulus and Mercury on successive mornings.

Tuesday, September 27

• This is the time of year when, during the evening, the dim Little Dipper "dumps water" into the bowl of the Big Dipper way down below. The Big Dipper will dump it back in the evenings of spring.

• As dawn brightens Wednesday morning the 28th, spot the thin crescent Moon between Regulus above it and Mercury below it, as shown at right.

Wednesday, September 28

• As dawn brightens Thursday morning the 29th, look for a super-thin crescent Moon near Mercury very low in the east. Start looking about 45 minutes before your local sunrise time. Binoculars will help as dawn grows bright.

Thursday, September 29

• The Two Top Miras. Chi Cygni now overhead in the evening, and Mira (Omicron Ceti) visible late at night, are the two brightest Mira-type stars in the sky: long-period red variables. Chi Cyg should be at or just past its maximum brightness, 5th magnitude or so. Mira should be nearly at its minimum, 8th or 9th mag. Follow them through the coming months with the article and finder charts in the October Sky & Telescope, page 49. As one brightens and the other dims, when will they pass each other in brightness?

Friday, September 30

• This is the time of year when the Little Dipper extends left from Polaris after dark. The Little Dipper's only two bright stars are Polaris, the end of the Dipper's handle, and Kochab, the lip of its bowl. Both are 2nd magnitude. They're exactly level with each other about a half hour after dark now, depending on your latitude.

• New Moon (exact at 8:11 p.m. Eastern Daylight Time).

Saturday, October 1

• As Deneb takes over from Vega as the star at the zenith after dark (for mid-northern latitudes), dim Capricornus takes over from Sagittarius as the zodiacal constellation standing due south. It is ever thus.

[ilan]

Why time travel isn’t possible
Eleanor Imster in Human World | September 26, 2106

Bottom line: Video explores the possibility of time travel, and the nature of time and space.

A simple question from his wife – Does physics really allow people to travel back in time? – propelled Berkeley physicist Richard Muller on a quest to resolve a fundamental problem that had puzzled him throughout his 45-year career: Why does the arrow of time flow inexorably toward the future, constantly creating new “nows”?

In the video, you’ll hear Muller propose a way to test his theory using LIGO. The Laser Interferometer Gravitational-Wave Observatory (LIGO) consists of two widely separated installations within the United States – one in Hanford Washington and the other in Livingston, Louisiana – operated in unison as a single observatory. The LIGO Scientific Collaboration is a group of scientists seeking to make the first direct detection of gravitational waves created by merging black holes, and use them to explore the fundamental physics of gravity.

Video:

https://www.youtube.com/watch?v=FYxUzm7gQkY&feature=youtu.be

Added image to article for spice. - Ilan

[ilan]

Elon Musk Unveils His Plan For Colonizing Mars (Video)
NPR | September 27, 201612:30 PM ET

Elon Musk, CEO and CTO of SpaceX, introduces the Dragon V2 spaceship at the company's headquarters in Hawthorne, Calif., in May 2014. Musk predicted during an interview at the Code Conference in Southern California on June 1 that people would be on Mars in 2025. Jae C. Hong/AP

Billionaire tech entrepreneur Elon Musk says his space transport company, SpaceX, will build a rocket system capable of taking people to Mars and supporting a permanent city on the red planet.

"It's something we can do in our lifetimes," he said in a speech Tuesday at the International Astronautical Congress in Guadalajara, Mexico, that was streamed online and watched by more than 100,000 people. "You could go."

Musk described plans to send at least a million humans to Mars and establish a self-sustaining city there. He said he expects people to reach Mars within a decade, and described four requirements for a new rocket fleet, which would travel to Mars approximately every two years, when Mars and Earth come closest to each other.

The requirements for a feasible rocket system are full re-usability, the ability to refuel in orbit, the ability to produce fuel on Mars and identifying the ideal propellant. Because the atmosphere of Mars is largely made of carbon dioxide, and previous missions have found ice on the planet, Musk said he though it would be possible to produce a methane fuel there.

But the centerpiece of the speech was a video simulation of a the massive spacecraft and rocket to get Mars colonizers to their destination. (Within SpaceX, they have been nicknamed the "BFS" and "BFR," which are acronyms for phrases NPR is too polite to spell out.)

One thing Musk was less specific about was who would pay for it all, saying it would be "a huge public private partnership," and that he expected support to "snowball." He did say the cost per person would need to decrease significantly in order for colonization to work. Right now, Musk estimates a trip to Mars would cost $10 billion per person. Musk says he would like to bring that cost down to about $200,000.

Musk is very wealthy, and said in his speech that his "only motivation" for amassing personal wealth is to work on making life multi-planetary. He is simultaneously supporting SpaceX, Tesla Motors and SolarCity.

The speech also comes just weeks after a high-profile SpaceX failure: An unmanned rocket and its payload were destroyed in an explosion two days before the rocket was scheduled to launch.

It's not the first setback for SpaceX, which has seen rockets explode before — and, as the Two-Way reported, came after a series of successes for the company. But Musk called it the company's "most difficult and complex failure we have ever had in 14 years."

The Guardian notes that Musk's "fail-fast" approach to rocket-building is intentional, and tied to his ambition. But the explosion has led some to question whether SpaceX can reliably send cargo to the International Space Station, "let alone take people to Mars," the newspaper writes.

Video:

https://youtu.be/0qo78R_yYFA

[ilan]

How Two Astronomers Accidentally Discovered the Big Bang (Video)
The Big Story

Nowadays, it's a universally accepted theory that the universe began 13.8 billion years ago with the Big Bang. But did you know that two radio astronomers unintentionally stumbled upon its discovery? In the 1960s, Robert Wilson and Arno Penzias were measuring the brightness of the sky with their radio telescope. No matter where they pointed it, they picked up an inexplicable droning sound. What initially sounded like a mistake ended up being the discovery of a lifetime.

Video:

https://youtu.be/cPalHdzsImc

[ilan]

Can you find the Big Dipper?
Deborah Byrd in Tonight (EarthSky) | October 1, 2016

Tonight … can you find the Big Dipper at nightfall and early evening? As seen from the Northern Hemisphere, this most famous of star patterns – the Big Dipper – lurks low in the northwest after sunset and quickly sinks below the horizon for those at southerly latitudes. It’s tough (or impossible) to spot the Big Dipper over the horizon on autumn evenings from the southern half of the united States. But the pattern is visible all night from northerly latitudes, albeit low in the sky. And, before dawn around now, we’ll all find the Big Dipper ascending in the northeast.

To find the Big Dipper’s place in the sky, remember the phrase: spring up and fall down. That’s because the Big Dipper shines way high in the sky on spring evenings but close to the horizon in autumn.

View larger. | Big Dipper on the horizon while getting set up at the Astronomical Society of New Haven‘s 25th annual Connecticut Star Party in Goshen, Connecticut, October 9-11, 2015. Photo by Kurt Zeppetello.

The distances of the stars in the Dipper reveal something interesting about them: five of these seven stars have a physical relationship in space. That’s not always true of patterns on our sky’s dome. Most star patterns are made up of unrelated stars at vastly different distances.

But Merak, Mizar, Alioth, Megrez and Phecda are part of a single star grouping. They probably were born together from a single cloud of gas and dust, and they’re still moving together as a family.

The other two stars in the Dipper – Dubhe and Alkaid – are unrelated to each other and to the other five. They are moving in an entirely different direction. Thus millions of years from now the Big Dipper will have lost its familiar dipper-like shape.

The Big Dipper makes up a part of the Ursa Major or Big Bear constellation. Image criedit: Old Book Art Image Gallery

[ilan]

Hints of Geysers Erupting from Europa
Kelly Beatty, Sky&Telescope | October 1, 2016

Newly released Hubble images show what appear to be towering jets of water coming from Jupiter's moon Europa.

In 1979, images from Voyagers 1 and 2 showed Jupiter's moon Europa to have a cracked but billiard-ball-smooth surface. Planetary geophysicists concluded that this icy world must have a deeply buried ocean, which must episodically flood the surface.

That's when astrobiologists started talked earnestly about the possibility that Europa's ocean might conceivably host life. But the putative ocean's depth below the ice crust is unknown, though it must be at least several miles thick — a formidable barrier to exploring it with submersible, life-seeking probes.

A Galileo orbiter image of Europa has been added to a just-released Hubble Space Telescope image of what might be towering geysers of water erupting from near the moon's south pole. NASA / ESA / W. Sparks / USGS Astrogeology Science Center

Yet sampling Europa's ocean might be easier than once thought. New results from the Hubble Space Telescope, announced this week, show what appear to be towering plumes of water jetting away from Europa's surface. Hints that Europa might have water-powered geysers first came to light in 2012, when a team led by Lorenz Roth (Southwest Research Institute) used HST to spectroscopically detect localized clouds of hydrogen and oxygen atoms in Europa's vicinity. It was tantalizing but not conclusive evidence.

The new results, though again not offering rock-solid proof, use an entirely different technique to suggest that Europa might be belching water into space. William Sparks (Space Telescope Science Institute) and others have used Hubble to record images of Europa as it crossed in front of Jupiter. They wanted to see if the moon had a thin atmosphere, which would show up as a dark aura around Europa when viewed in silhouette against Jupiter. (Other observers are trying to exploit this same transit technique to detect atmospheres around the planets of distant stars.)

[ilan]

Hubble probes the core of galaxy NGC 247
ESA/Hubble/NASA via Astronomy News | 3 October 2016

NGC 247 is a spiral galaxy in the Sculptor Group some 11 million light-years from Earth. This Hubble image shows a zoomed-in view of NGC 247’s central region. Image credit: ESA/Hubble & NASA.

This NASA/ESA Hubble Space Telescope image shows the central region of a spiral galaxy known as NGC 247. NGC 247 is a relatively small spiral galaxy in the southern constellation of Cetus (The Whale). Lying at a distance of around 11 million light-years from us, it forms part of the Sculptor Group, a loose collection of galaxies that also contains the more famous NGC 253 (otherwise known as the Sculptor Galaxy).

NGC 247’s nucleus is visible here as a bright, whitish patch, surrounded by a mixture of stars, gas and dust. The dust forms dark patches and filaments that are silhouetted against the background of stars, while the gas has formed into bright knots known as H II regions, mostly scattered throughout the galaxy’s arms and outer areas.

This galaxy displays one particularly unusual and mysterious feature — it is not visible in the image above, but can be seen clearly in wider views of the galaxy, such as the picture below from ESO’s MPG/ESO 2.2-metre telescope. The northern part of NGC 247’s disc (to the right in the following image) hosts an apparent void, a gap in the usual swarm of stars and H II regions that spans almost a third of the galaxy’s total length.

This picture of the spiral galaxy NGC 247 was taken using the Wide Field Imager (WFI) on the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory in Chile. Image credit: ESO.

There are stars within this void, but they are quite different from those around it. They are significantly older, and as a result much fainter and redder. This indicates that the star formation taking place across most of the galaxy’s disc has somehow been arrested in the void region, and has not taken place for around one billion years. Although astronomers are still unsure how the void formed, recent studies suggest it might have been caused by gravitational interactions with part of another galaxy.

[ilan]

Astronomers find a treasure trove of strange brown dwarfs
Mika McKinnon, Astronomy Magazine | Published: Monday, October 3, 2016

The new find adds to the population of “failed stars” and makes them even weirder than we thought.


NASA/JPL-Caltech/UCLA

Stars that didn’t quite make it to full blazing glory are a lot more common than we thought. A new survey found not just more brown dwarfs, but an entire population of ultracool brown dwarfs that aren’t identified by standard sky surveys.

Brown dwarfs are often teased as being failed stars, too big and bright to be a planet but too small to sustain hydrogen fusion. They’re doomed to stay dim until they sputter out, never achieving the bright twinkle of the stars that spot our skies. But this makes them perfect for observation: unlike other stars, brown dwarfs are dim enough to not blind instruments. They’re often in isolation, allowing for even more clear observation of this astrophysical intermediary between planets and stars.

A new survey led by Jasmin Robert of Université de Montréal went hunting for even more brown dwarfs. The team surveyed 28% of the sky, and checked the properties of every star. Instead of using the standard techniques to filter out brown dwarfs strictly by set color ranges, the team pulled full spectrums of stars to find more unusual brown dwarfs. They found an additional 165 ultracool brown dwarfs not previously identified within the study region. For brown dwarfs, ultracool is below 3,500F, a sixth the temperature of our Sun and barely warm enough to melt carbon.

Of the stars Robert and her team found, fully a third were unusual even in this odd population. The unusual ultracool brown dwarfs are ones that have different colors than anticipated for their age. They either appeared older than they are, tinted red through a disproportionally dusty atmosphere or inflated size, or younger than they are by being tinted blue by a scarcity of dust or contracted size. The discovery that the team identified so many unusual brown dwarfs so quickly in such a small patch of sky indicates that the population of brown dwarfs is more varied than we thought.

All of this means that it’s just gotten a whole lot easier to go hunting for brown dwarfs in the neighborhood.

[ilan]

Why is this star dimming? Astronomers still don't know
Rob Verger (Fox News, Astronomy) | October 05, 2016


This artist’s conception shows a star behind a shattered comet. (NASA/JPL-Caltech)

A strange star in our galaxy has officially become even more enigmatic: According to data collected by NASA’s Kepler space telescope, the star mysteriously dimmed over a period of a few years.

The star is called KIC 8462852, and it was already on scientists’ radar for fluctuations in its brightness. So two astronomers decided to study it more carefully, using images from Kepler. They discovered that from 2009 to 2012, the star’s brightness declined by just under 1 percent. Then, over a time period of six months, its brightness plunged by 2 percent. While news of their discovery first surfaced in August, their work has now been accepted for publication in an astronomy journal, the Carnegie Institution for Science announced on Monday.

“The steady brightness change in KIC 8462852 is pretty astounding,” Ben Montet, an astronomer and fellow at the University of Chicago, said in a statement. “Our highly accurate measurements over four years demonstrate that the star really is getting fainter with time. It is unprecedented for this type of star to slowly fade for years, and we don’t see anything else like it in the Kepler data.”

Montet is coauthor on the new study about the star, forthcoming in the Astrophysical Journal.

“This star was already completely unique because of its sporadic dimming episodes,” Josh Simon, an astronomer at Carnegie Science, said in the statement. “But now we see that it has other features that are just as strange, both slowly dimming for almost three years and then suddenly getting fainter much more rapidly.”

One explanation for the star’s change in brightness is something like a planet or comet breaking up in front of it, although that idea doesn't fully account for the star's behavior, according to the study.

While the controversial concept that an “alien megastructure” could have caused the dimming has galvanized public interest in the star, David Kipping, an astronomer with Columbia University, said that it’s likely caused by an as-yet-to-be explained natural phenomenon.

“The confirmation that the star is dimming over time re-enforces how strange this star is,” Kipping told FoxNews.com in an email. “As yet, we do not have a natural explanation as to what is happening, but in my view this most likely represents a gap in our present knowledge rather than evidence for an alien megastructure.”

[ilan]

Hole in Galaxy 4.5 Billion Light-Years Away
Enrico de Lazaro, Sci-News | Oct 7, 2016

A rogue black hole has been found in the outer regions of the lenticular galaxy SDSS J141711.07+522540.8 (GJ1417+52 for short). Evidence suggests this black hole has a mass of approximately 100,000 solar masses, and was originally located in a dwarf satellite galaxy that collided and merged with a larger one.

This Hubble image shows the lenticular galaxy GJ1417+52. Image credit: NASA / ESA / Hubble.

Astronomers know that black holes ranging from about 10 times to 100 times the Sun’s mass are the remnants of dying stars, and that supermassive black holes, with some 100,000 to 10 billion times the Sun’s mass, inhabit the centers of most galaxies.

But scattered across the Universe are a few apparent black holes of a more mysterious type. Ranging from 100 to 100,000 solar masses, these intermediate-mass black holes are much harder to find.

According to scientists, both supermassive and intermediate-mass black holes may be found away from the center of a galaxy following a collision and merger with another galaxy containing a massive black hole.

As the stars, gas and dust from the second galaxy move through the first one, its black hole would move with it.

Now, a team of astronomers led by University of New Hampshire scientist Dacheng Lin has used NASA’s Chandra and ESA’s XMM-Newton X-ray observatories to discover a ‘wandering’ black hole in GJ1417+52, a lenticular galaxy located approximately 4.5 billion light-years away from us.

Dacheng Lin et al discovered a ‘wandering’ black hole in the lenticular galaxy GJ1417+52. The main panel has a wide-field, optical light image from Hubble. The black hole and its host galaxy are located within the box in the upper left. The inset on the left contains Hubble’s close-up view of GJ1417+52. Within this inset the circle shows a point-like source on the northern outskirts of the galaxy that may be associated with XJ1417+52. The inset on the right is Chandra’s X-ray image of XJ1417+52 in purple, covering the same region as the Hubble close-up. Image credit: X-ray – NASA / CXC / UNH / Dacheng Lin et al; optical – NASA / STScI.

This object, dubbed 3XMM J141711.1+522541 (XJ1417+52 for short), is located at a projected offset of 17,000 light-years from the nucleus of GJ1417+52.

It was discovered during long observations of a special region, the so-called Extended Groth Strip, with XMM-Newton and Chandra data obtained between 2000 and 2002.

Its extreme brightness makes it likely that it is a black hole with a mass estimated to be about 100,000 times that of the Sun, assuming that the radiation force on surrounding matter equals the gravitational force.

The Chandra data show XJ1417+52 gave off a tremendous amount of X-rays, which classifies it as a hyperluminous X-ray source (HLX). These are objects that are 10,000 to 100,000 times more luminous in X-rays than stellar black holes, and 10 to 100 times more powerful than ultraluminous X-ray sources (ULXs).

At its peak XJ1417+52 is about 10 times more luminous than the brightest X-ray source ever seen for a wandering black hole. It is also about 10 times more distant than the previous record holder for a wandering black hole.

The bright X-ray emission from this type of black hole comes from material falling toward it. The X-rays from XJ1417+52 reached peak brightness between 2000 and 2002.

Dr. Lin and co-authors theorize that this outburst occurred when a star passed too close to the black hole and was torn apart by tidal forces.