Earlier this year, astronomers discovered what appeared to be a pair of
supermassive black holes circling toward a collision so powerful it
would send a burst of gravitational waves surging through the fabric of
space-time itself.
Now, in a new study in the journal Nature,
astronomers at Columbia University provide additional evidence that a
pair of closely orbiting black holes is causing the rhythmic flashes of
light coming from quasar PG 1302-102.
Based on calculations of the pair’s mass—together, and relative to each
other—the researchers go on to predict a smashup 100,000 years from
now, an impossibly long time to humans but the blink of an eye to a star
or black hole. Spiraling together 3.5 billion light-years
away, deep in the Virgo constellation, the pair is separated by a mere
light-week. By contrast, the closest previously confirmed black hole pair is separated by 20 light-years.
Just 15 minutes after its closest approach to Pluto on July 14, 2015,
NASA’s New Horizons spacecraft looked back toward the sun and captured
this near-sunset view of the rugged, icy mountains and flat ice plains
extending to Pluto’s horizon. The smooth expanse of the informally named
icy plain Sputnik Planum (right) is flanked to the west (left) by
rugged mountains up to 3,500 meters high, including the informally named
Norgay Montes in the foreground and Hillary Montes on the skyline. To
the right, east of Sputnik, rougher terrain is cut by apparent glaciers.
The backlighting highlights over a dozen layers of haze in Pluto’s
tenuous but distended atmosphere. The image was taken from a distance of
18,000 kilometers to Pluto; the scene is 1,250 kilometers wide.
First off, what is the One-Year Crew? Obviously, they’re doing something for a year, but what, and why?
Two crew members on the International Space Station have just met the halfway point of their year in space. NASA Astronaut Scott Kelly and Russian Cosmonaut Mikhail Kornienko are living in space for 342 days and will help us better understand the effects of microgravity on the human body.
Why 342 days and not 365? Thought you might ask. Due to crew rotation schedules, which involve training timelines and dictate when launches and landings occur, the mission was confined to 342 days. Plenty of time to conduct great research though!
The studies performed throughout their stay will yield beneficial knowledge on the medical, psychological and biomedical challenges faced by astronauts during long-duration spaceflight.
The weightlessness of the space environment has various effects on the human body, including: Fluid shifts that cause changes in vision, rapid bone loss, disturbances to sensorimotor ability, weakened muscles and more.
The goal of the One-Year Mission is to understand and minimize these effects on humans while in space.
The Twins Study
A unique investigation that is being conducted during this year in space is the Twins Study. NASA Astronaut Scott Kelly’s twin brother Mark Kelly will spend the year on Earth while Scott is in space. Since their genetic makeup is as close to identical as we can get, this allows a unique research perspective. We can now compare all of the results from Scott Kelly in space to his brother Mark on Earth.
But why are we studying all of this? If we want to move forward with our journey to Mars and travel into deep space, astronauts will need to live in microgravity for long periods of time. In order to mitigate the effects of long duration spaceflight on the human body, we need to understand the causes. The One-Year mission hopes to find these answers.
Halfway Point
Today, September 15 marks the halfway point of their year in space, and they now enter the final stretch of their mission.
Here are a few fun tidbits on human spaceflight to put things in perspective:
1) Scott Kelly has logged 180 days in space on his three previous flights, two of which were Space Shuttle missions.
2) The American astronaut with the most cumulative time in space is Mkie Fincke, with 382 days in space on three flights. Kelly will surpass this record for most cumulative time in space by a U.S. astronaut on October 16.
3) Kelly will pass Mike Lopez-Alegria’s mark for most time on a single spaceflight (215 days) on October 29.
4) By the end of this one-year mission, Kelly will have traveled for 342 days, made 5,472 orbits and traveled 141.7 million miles in a single mission.
Have you seen the amazing images that Astronaut Scott Kelly has shared during the first half of his year in space? Check out this collection, and also follow him on social media to see what he posts for the duration of his #YearInSpace: Facebook, Twitter, Instagram.
if, as characterized, this is an early-warning defense satellite (e.g. infrared observation to detect ballistic missile heat blooms), it makes complete sense: china has had a no-first-use policy for decades (since 1964!), but the us has never been willing to cross that particular bridge. also, the us has around 5000 warheads to china’s 140 or so.
Many people from all of the Philae and Rosetta teams have worked very
hard over the past few months to try and return Philae to full
operational status, and these efforts will certainly continue. Current
thinking is that the problems being experienced with Philae’s
communications hardware are probably due to the very low temperatures
experienced by the lander in the months immediately following its
landing at the dark Abydos location.
But as communications were re-established on 13 June and then
intermittently on several occasions since then, it is hoped that the
constantly changing thermal conditions on Comet 67P/C-G will make it
possible for the hardware to return to a more stable state, to
re-establish contact, and to continue Philae’s unprecedented scientific
measurements from the surface of the comet, a key part of Rosetta’s
overall mission.
“The
galaxy we have observed, EGS8p7, which is unusually luminous, may be
powered by a population of unusually hot stars, and it may have special
properties that enabled it to create a large bubble of ionized hydrogen
much earlier than is possible for more typical galaxies at these times,”
says Sirio Belli, a Caltech graduate student who worked on the project.
“We
are currently calculating more thoroughly the exact chances of finding
this galaxy and seeing this emission from it, and to understand whether
we need to revise the timeline of the reionization, which is one of the
major key questions to answer in our understanding of the evolution of
the universe,” Zitrin says.
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