YouTube / MinuteEarth
YouTube / MinuteEarth

Why Do We Only See One Side of the Moon?

YouTube / MinuteEarth
YouTube / MinuteEarth

When I was a kid, I thought the dark side of the moon (also known as "the far side") was a metaphor. (I can't tell you what I thought that metaphor was supposed to mean; perhaps it just represented something mythically inaccessible.) I figured certainly the moon must rotate while it orbits, so we must eventually see all of it, right? I was in high school before I was disabused of this notion, despite having looked at the moon plenty of times and apparently not noticing its utter sameness, which was strong evidence that indeed I was always seeing one side of it.

I recall in high school seeing a demonstration of how the rotation of the earth and the moon matched up, and it blew my mind even more than that one Pink Floyd record. If you haven't seen this demo (or perhaps have forgotten the specifics), spend two minutes learning why there is an earth side and a far side of the moon:

This is another video from the excellent (and relatively new) MinuteEarth YouTube channel. They answer lots of "I hadn't thought to ask that" questions in a succinct way, and cite their sources in the video descriptions. Good stuff!

Strongly recommended related viewing: Video Shows Phases of the Moon from its Dark Side.

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ESO, A. Müller et al.
Here's the First Confirmed Image of a Planet Being Born
ESO, A. Müller et al.
ESO, A. Müller et al.

One of the newest landmarks in the observable universe has finally been captured, according to the European Southern Observatory. The image, snapped at its Very Large Telescope (VLT) in Chile, marks the first time a newborn planet has been seen as it forms. 

The image was documented by SPHERE, an instrument at the VLT that's built to identify exoplanets. It shows a planet, dubbed PDS 70b, taking shape in the disc of gas and star dust surrounding the young dwarf star PDS 70. In the past, astronomers have caught glimpses of what may have been new planets forming, but until now it had been impossible to tell whether such images just showed shapes in the dust or the beginnings of true planet formation. The results of the research will be shared in the journal Astronomy & Astrophysics [PDF].

This latest cornograph (an image that blocks the light of a star to make its surroundings visible) depicts the new planet clearly as a bright blob beside the black star. The two bodies may look close in the photo, but PDS 70b is roughly 1.8 billion miles from PDS 70, or the distance of Uranus to the Sun. SPHERE also recorded the planet's brightness at different wavelengths. Based on information gathered from the instrument, a team of scientists led by Miriam Keppler of the Max Planck Institute for Astronomy says that PDS 70b is a gas giant a few times the mass of Jupiter with a surface temperature around 1830°F and a cloudy atmosphere.

Astronomers known that planets form from solar clouds which stars leave behind when they come into a being, but until now, the details surrounding the phenomena have been mysterious. “Keppler’s results give us a new window onto the complex and poorly understood early stages of planetary evolution,” astronomer André Müller said in a press release. “We needed to observe a planet in a young star’s disc to really understand the processes behind planet formation.”

This is just the latest history-making image captured by the ESO's Very Large Telescope. In the last 20 years, it has documented nebulae, light from gravitational waves, and interacting galaxies.

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iStock
Saturn and a Strawberry Moon Will Brighten Night Skies This Week
iStock
iStock

Summer has officially arrived. That means the weather is finally warm enough in parts of the country to lay down a blanket in your backyard and spend the night staring at the sky. This week is especially exciting for stargazers. According to Mashable, Saturn will be visible in the sky beside a "strawberry moon."

One of the first major celestial events of the season takes place Wednesday, June 27. The Earth will fall directly between Saturn and the Sun on Wednesday and a brightly shining Saturn will be visible in the eastern sky after the Sun goes down. The best time to spot the ringed planet is around midnight, and it will appear in the sky for the next several months.

On Wednesday, when Saturn is at its brightest, the sky will present another treat. A full strawberry moon will rise not far from Saturn's spot around 12:53 a.m. EDT that night and accompany the planet as it moves across the sky. The name isn't a reference to the Moon's hue, but to the time of year when it appears: A strawberry moon is the first full moon of summer, and it was once used by farmers to mark the beginning of strawberry picking season.

These two events are just the start of a promising time of year for astronomy fans. Sync your digital planner to this space calendar so you don't miss out on any other big dates, like the partial solar eclipse on August 11.

[h/t Mashable]

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