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Science News Staff

Science Ticker

Science Ticker

Measured distance within the Milky Way gives clues to what our galaxy looks like

illustration of Milky Way

FROM THE INSIDE OUT  The best images of the Milky Way are artist’s impressions like this one, as it’s difficult to map the galaxy from our position inside it. But new measurements will give us more direct clues to what the Milky Way actually looks like.

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For the first time, astronomers have directly measured the distance to a spot clear across the galaxy. The established but challenging technique promises a new way to map the structure of the Milky Way.

This technique, called parallax, has measured distances to stars since the 1830s. But because of galactic dust in the way, it has been difficult to use parallax on stars on the opposite side of the galaxy. Other ways to measure distance are saddled with assumptions and uncertainties.

Alberto Sanna of the Max Planck Institute for Radio Astronomy in Bonn, Germany, and his colleagues used the Very Long Baseline Array of radio telescopes in New Mexico to track a star-forming region in the outer Scutum-Centaurus spiral arm, which is on the opposite side of the Milky Way from the local arm where the sun resides. The scientists report in the October 13 Science that the region is more than 66,500 light-years away.

The team observed the distant spot from March 2014 to March 2015, and drew an imaginary triangle between it and two points in Earth’s orbit. They then used trigonometry to measure the distance.

“Our measurement is essentially the same as a surveyor uses to locate points on the Earth,” says study coauthor Mark Reid of the Harvard-Smithsonian Center for Astrophysics. “It requires no model or assumptions.”

Applying the same technique to other regions of the Milky Way will help astronomers figure out what our galaxy looks like from the outside and compare it to other spiral galaxies.

“We predict that, within the next 10 years, we will be able to answer the question: What does the Milky Way look like?” Sanna says.

Animals,, Oceans,, Conservation

New deep-sea sponge could play a starring role in monitoring ocean health

By Carolyn Gramling 7:00am, October 10, 2017
A new species of sponge that dwells on metal-rich rocks could help scientists track the environmental impact of deep-sea mining.
Animals,, Paleontology

Ancient whale turns up on wrong side of the world

By Laurel Hamers 12:00pm, October 9, 2017
A Southern Hemisphere whale species was briefly a northern resident.
Chemistry,, Technology

Cool way to peer into molecules’ inner workings wins chemistry Nobel Prize

By Laurel Hamers 8:04am, October 4, 2017
Three scientists will split the prize for their work developing cryo-electron microscopy.
Paleontology,, Animals

A baby ichthyosaur’s last meal revealed

By Helen Thompson 2:00am, October 3, 2017
A new look at an old fossil shows that some species of baby ichthyosaurs may have dined on squid.
Physiology,, Biomedicine

Body clock mechanics wins U.S. trio the Nobel Prize in physiology or medicine

By Tina Hesman Saey 6:41am, October 2, 2017
The cellular mechanisms governing circadian rhythms was a Nobel Prize‒winning discover for three Americans.

Bedbugs may be into dirty laundry

By Helen Thompson 9:00am, September 28, 2017
When humans aren’t around, bedbugs go for the next best thing: smelly human laundry.

Saber-toothed kittens were born armed to pounce

By Carolyn Gramling 2:00pm, September 27, 2017
Even as babies, saber-toothed cats had not only oversized canine teeth but also unusually powerful forelimbs.
Paleontology,, Animals

This giant marsupial was a seasonal migrant

By Laurel Hamers 7:05pm, September 26, 2017
The giant, extinct marsupial Diprotodon optatum migrated seasonally, the first marsupial shown to do so.

About 1 in 5 teens has had a concussion

By Aimee Cunningham 11:00am, September 26, 2017
Almost 20 percent of U.S. teens have had at least one diagnosed concussion in the past, an analysis of a 2016 national survey finds.

Plate tectonics started at least 3.5 billion years ago

By Carolyn Gramling 3:12pm, September 21, 2017
Analyses of titanium in rock suggest plate tectonics began 500 million years earlier than thought.
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