Milky Way Over Storm Lake, IA

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If Earth had Saturn’s Rings

From an excellent post by Jason Davis

From Washington, D.C., the rings would only fill a portion of the sky, but appear striking nonetheless. Here, we see them at sunrise.

From Guatemala, only 14 degrees above the equator, the rings would begin to stretch across the horizon. Their reflected light would make the moon much brighter.

From Earth’s equator, Saturn’s rings would be viewed edge-on, appearing as a thin, bright line bisecting the sky.

At the March and September equinoxes, the Sun would be positioned directly over the rings, casting a dramatic shadow at the equator.

At midnight at the Tropic of Capricorn, which sits at 23 degrees south latitude, the Earth casts a shadow over the middle of the rings, while the outer portions remain lit.

via x

100th Anniversary of Einstein’s Theory of Relativity

One hundred years ago this month, Albert Einstein published his theory of general relativity (GR), one of the most important scientific achievements in the last century.

A key result of Einstein’s theory is that matter warps space-time, and thus a massive object can cause an observable bending of light from a background object. The first success of the theory was the observation, during a solar eclipse, that light from a distant background star was deflected by the predicted amount as it passed near the sun.

When Einstein developed the general theory of relativity, he was trying to improve our understanding of how the universe works. At the time, Newtonian gravity was more than sufficient for any practical gravity calculations. However, as often happens in physics, general relativity has applications that would not have been foreseen by Einstein or his contemporaries.

How many of us have used a smartphone to get directions? Or to tag our location on social media? Or to find a recommendation for a nearby restaurant? These activities depend on GPS. GPS uses radio signals from a network of satellites orbiting Earth at an altitude of 20,000 km to pinpoint the location of a GPS receiver. The accuracy of GPS positioning depends on precision in time measurements of billionths of a second. To achieve such timing precision, however, relativity must be taken into account.

Our Gravity Probe B (GP-B) mission has confirmed two key predictions derived from Albert Einstein’s general theory of relativity, which the spacecraft was designed to test. The experiment, launched in 2004, and measured the warping of space and time around a gravitational body, and frame-dragging, the amount a spinning object pulls space and time with it as it rotates.

Scientists continue to look for cracks in the theory, testing general relativity predictions using laboratory experiments and astronomical observations. For the past century, Einstein’s theory of gravity has passed every hurdle.

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30 Doradus, located in the heart of the Tarantula nebula, is the brightest star-forming region in our galactic neighborhood. The nebula resides 170,000 light-years away in the Large Magellanic Cloud.

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Credit to anactualbee.tumblr.com

Daily Affirmation 386.

Your asexuality is not something you should be ashamed of. Your asexuality is not something that you should regret because of how it might affect your relationships. Your asexuality is not bad, regrettable, or shameful.

Daily Affirmation 394.

You are allowed to have trouble accepting your identity. You are allowed to struggle with your asexuality. It is not easy, or comfortable to be questioning or avoiding parts of yourself, but it is normal. It is human. And it does not mean that anyone else is allowed to invalidate who you are.

“I AM NOT BROKEN.” asexual

please message me, @hopeunconditional, if you would like a digital piece of similar style with a different pride flag.

aromantic - bisexual

you don’t hug asexuals you embrace them

How Well Do You Know Your Space Photos?

Can you guess the subject of each of these pictures? How many will you get right? Test your friends and family to see who knows their space photos the best.

1. Ice on Earth or a Picture of Mars?

2. Dry Land on Earth or a Close-Up of Jupiter?

3. Mercury or Our Moon?

4. Do You Think This is Mars or Our Home Planet?

5. Waves on Jupiter or Saturn?

6. Is this a picture of Mars or Earth?

7. Can You Tell Which is Europa and Which is the Bottom of a Frying Pan?

8. Close-Up of Our Moon or Dwarf Planet Ceres?

9. A Weird World or Our Own World?

10. The Red Planet or a Red Desert?

Answers

1. Mars. You might be surprised, but this image taken by our Mars Reconnaissance Orbiter is of a light-toned deposit on the Martian surface. Some shapes in the terrain suggest erosion by a fluid moving north to south.

2. Earth. This image taken by our Earth Observing-1 satellite shows Lake Frome in central Australia. In this image, the salt lake appears bone-dry, filled with off-white sediment. This area of Australia receives 149 to 216 millimeters of rainfall a year on average, and the basins pass most of their time as saltpans.

3. Mercury. Our MESSENGER spacecraft captured this image of Mercury during a fly by in October 2008. It shows previously uncharted regions of the planet that have large craters with an internal smoothness similar to Earth’s own moon. It is thought that these craters were to have been flooded by lava flows that are old but not as old as the surrounding more highly cratered surface.

4. Earth. Surprisingly, this image take from the International Space Station shows the western half of the Arabian peninsula in Saudi Arabia. It not only contains large expanses of sand and gravel, but extensive lava fields known as haraat.

5. Saturn. Although this pattern of waves is similar to those seen on Jupiter, this is actually a picture of Saturn. The pattern of an iconic surfer’s wave, has been observed in many places all over the universe, including at the edges of Earth’s magnetic environment.

6. Mars. This image was taken by our Mars Reconnaissance Orbiter and shows dunes of sand-sized materials that have been trapped on the floors of many Martian craters. The dunes are linear, thought to be due to shifting wind directions.

7. Left: Europa. Right: Frying Pan. Europa is one of Jupiter’s moons, and is about the same size as Earth’s moon.

8. Ceres. This image taken by our Dawn spacecraft shows an intriguing mountain on dwarf planet Ceres protruding from a relatively smooth area.

9. Earth. This image of the Bazman volcano is located in a remote region of souther Iran. While the volcano has the classic cone shape of a stratovolcano, it is also heavily dissected by channels that extend downwards from the summit.

10. Earth. This image of the Great Sandy Desert in northwest Australia shows a variety of dune forms across the region. The photo was taken by the Expedition 35 crew from the International Space Station.

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