Coalition of the Confused

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Confused malcontents swilling Chardonnay while awaiting the Zombie Apocalypse.

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The Solar System   Science

Started 5/17/18 by Jenifer (Zarknorph); 31347 views.
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Jenifer (Zarknorph)
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From: Jenifer (Zarknorph)

6/21/18

Mysterious mountain waves in Venus's atmosphere put new spin on a day

Magellan: Venus False-Color Terrain

This visualization is a brief tour of the global terrain of the planet Venus as revealed by radar onboard the Magellan spacecraft. The height of the terrain ...

A mysterious bow-shaped "gravity" cloud that hovers over mountains on Venus could speed up the planet's day by a couple of minutes, according to a study.

Key points

  • We don't know exactly how long it takes Venus to complete a single rotation.
  • New modelling shows fleeting formation of massive mountain waves in atmosphere may speed up rotation at surface
  • Understanding rotation rate can help us understand other mysteries such as what lies at Venus's core

The study, published today in Nature Geoscience, may help explain variations in the planet's rotation seen by different spacecraft over the years.

Venus spins at a leisurely pace, taking an average of 243 Earth days to complete one full rotation.

Measurements taken 16 Earth years apart by the Magellan and Venus Express missions differ by up to seven minutes, said Thomas Navarro, a planetary scientist at the University of California, Los Angeles.

"It is very difficult to measure the rotation rate because Venus rotates very slowly," Dr Navarro said.

"We have to average the displacement over a long period of time to get an estimate.

"We kind of know what the average duration of the day is, what we don't know very well is how the fluctuations of the rotation rate could make the day vary."

Slow planet vs super-fast atmosphere

Venus is also hard to study because it is shrouded in thick clouds of sulfuric acid.

Unlike the leisurely pace taken by the planet itself, these clouds rip right around Venus in just four to five Earth days.

"We do not understand much about why the atmosphere is super rotating," Dr Navarro said.

But not all the atmosphere appears to super rotate.

Recently, the Japane
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Jenifer (Zarknorph)
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From: Jenifer (Zarknorph)

7/25/18

The Quest for the Holy Grail continues

Image result for ice age on mars

In a massive shot in the arm for the search for life on Mars, a giant lake of liquid water seems to be buried beneath the ice near the Red Planet's south pole.

Key points:

  • The search for liquid water on Mars has, so far, been unsuccessful
  • What appears to be a 20-kilometre-wide subsurface "lake" near Mars's south pole has been detected by the MARSIS ground-penetrating radar instrument on the Mars Express spacecraft
  • If the lake is part of a wider network, life in microbial form could theoretically survive there today

Using ground-penetrating radar on an orbiting spacecraft, an Italian team picked up signs of a 20-kilometre-wide body of liquid water, hidden 1.5 kilometres under the ice cap.

They published their observations in Sciencetoday.

Whether that body of water is a relic of past oceans or part of a bigger network of subterranean lakes is still a mystery, said Roberto Orosei, a planetary scientist at the Italian National Institute of Astrophysics and lead author of the paper.

"We need to determine if this discovery is unique or if it's something that exists elsewhere on Mars," he said.

Whether it's a one-off or not, he added, has important implications for finding life lurking on Mars today.

Image result for mars ice caps

"This [bright reflection] is what you see in places like Antarctica, over Lake Vostok and other subglacial lakes," Dr Orosei said.

But whether the Martian subsurface lake is mostly pure water or sludgy sediment remains to be seen.

The MARSIS instrument can't tell us how deep the water is or how much stuff is mixed with it.

It could be pure water, maybe a metre deep or so, or water-saturated sediments tens of metres thick, Dr Orosei said. Both scenarios would produce the same radar signal.

So what can we deduce about the lake?

To stay liquid in such frigid conditions, the lake must be salty.

Dissolved salts lower water's freezing point — seawater on Earth, for instance, freezes at minus 2 degrees Celsius.

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From: Jenifer (Zarknorph)

7/28/18

Blood Moon last night, but I missed it

The lunar eclipse seen around 4:00am on Saturday morning.

Curiosity and awe have greeted a complete lunar eclipse, the longest one of this century and visible in much of the world.

The so-called "blood moon," when it turns a deep red, was visible at different times in Australia, Africa, Asia, Europe and South America when the sun, Earth and moon lined up perfectly, casting Earth's shadow on the moon.

The total eclipse lasted one hour, 42 minutes and 57 seconds, though a partial eclipse preceded and followed it, meaning the Moon spent a total of three hours and 54 minutes in the Earth's umbral shadow, according to NASA.

A total lunar eclipse occurs when the Earth's shadow moves across the Moon, blocking out light from the Sun.

"What it actually shows is the solar system in action, and it gives you a bit of a better perspective of your own place in the scheme of things, in the universe," he said.

Astrophysicist at the Australian National University Brad Tucker said a total lunar eclipse is something even experts get excited about.

"The Moon passes into the Earth's shadow and that red colour really is the atmosphere of our Earth covering the light to bed.

"So you're actually seeing … the sunrise and the sunset of the Earth simultaneously," he said.


Pictures to follow

Di (amina046)

From: Di (amina046)

8/12/18

Jenifer (Zarknorph)
Host

From: Jenifer (Zarknorph)

8/12/18

I heard it got delayed at the last minute..

Jenifer (Zarknorph)
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From: Jenifer (Zarknorph)

8/13/18

Just saw the story!

Glad they fixed the problem!

'Finally go up and touch the sun'

By better understanding the sun's life-giving and sometimes violent nature, Earthlings can better protect satellites and astronauts in orbit, and power grids on the ground, he noted.

In today's tech-dependent society, everyone stands to benefit.

With this mission, scientists hope to unlock the many mysteries of the sun, a commonplace yellow dwarf star around 4.5 billion years old.

Illustration of solar space probes planned timeline

Among the puzzlers: Why is the corona hundreds of times hotter than the surface of the sun and why is the sun's atmosphere continually expanding and accelerating, as the University of Chicago's Mr Parker accurately predicted in 1958?

"The only way we can do that is to finally go up and touch the sun," Mr Fox said.

"We've looked at it. We've studied it from missions that are close in, even as close as the planet Mercury. But we have to go there."

The spacecraft's heat shield will serve as an umbrella, shading the science instruments during the close, critical solar junctures.

Sensors on the spacecraft will make certain the heat shield faces the sun at the right times.

If there's any tilting, the spacecraft will correct itself so nothing gets fried.

With a communication lag time of 8 minutes each way, the spacecraft must fend for itself at the sun. The Johns Hopkins flight controllers in Laurel, Maryland, will be too far away to help.

A mission to get close up and personal with our star has been on NASA's books since 1958.

The trick was making the spacecraft small, compact and light enough to travel at incredible speeds, while surviving the sun's punishing environment and the extreme change in temperature when the spacecraft is out near Venus.

"We've had to wait so long for our technology to catch up with our dreams," Mr Fox said.

"It's incredible to be standing here today."

More than 1 million names are aboard the spacecraft, submitted last spring by space enthusiasts, as well as photos of Mr Parker, the man, and a copy of his 1958 landmark paper on solar wind.

"I'll bet you 10 bucks it works," Mr Parker said.

Di (amina046)

From: Di (amina046)

8/13/18

Our world! Everyone goes sunbathing somewhere, how many heard about Mr. Parker?

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Di (amina046)

From: Di (amina046)

8/13/18

NASA's Parker Solar Probe Is Named for Him. 60 Years Ago, No One Believed His Ideas About the Sun.

Eugene N. Parker predicted the existence of solar wind in 1958. The NASA spacecraft is the first named for a living person.

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