by D. Middleton, March 24, 2020 in WUWT
One of the things I love about writing for Watts Up With That, is the fact that reader comments often inspire me to research and write subsequent posts. In my recent post about the origins of the Moon, one commentator suggested that the rate of lunar recession (tidal acceleration) indicated that the Earth was much younger than 4.5 billion years old and/or somehow disproved the geological Principle of Uniformitarianism. I didn’t give much thought to my reply. I simply calculated the distance from the Earth to the Moon 1 billion and 4.5 billion years ago. The Moon is currently receding (moving away) from the Earth at a rate of about 3.8 cm/yr. This has been directly measured with lasers.
At 3.8 cm/yr, the Moon would have been 215,288 miles away from Earth a billion years ago. It is currently an average of 238,900 miles away. At 3.8 cm/yr, it still would have been 132,646 miles away 4.5 BY.
If the Moon did did originate from a collision with Earth, it would have been a lot closer to Earth 4.5 BY than 100,000 miles.
by R.G. Andrews, December 13, 2019 in NationalGeography
Scientists scouring the lunar surface for clues to past impact rates found a bonus feature that has geologists “thoroughly confused.”
Sometime after the solar system formed 4.6 billion years ago, a projectile slammed into Earth’s youthful moon and formed the 620-mile-wide basin known as the Crisium basin. No one knows exactly when this impact happened, but for decades scientists have been trying to solve the puzzle as part of a larger debate over whether the moon and, by proxy, Earth endured a period of frenzied meteor bombardment in their early histories.
Now, scientists scouring the region say they’ve spotted a crater within the basin that appears to contain pristine impact melt, a type of volcanic rock that can act like a definitive geologic clock. If future astronauts or a robot could obtain a sample and tease out its age, that may help reveal what was happening on Earth during the primordial period when life first emerged on our planet.
And, as an added bonus, the discovery comes with an intriguing mystery: The basin also holds a geologic blister the size of Washington, D.C., that’s unlike anything else seen in the solar system. As the team reports in an upcoming paper in the Journal of Geophysical Research: Planets, this volcanic lump appears to have been inflated and cracked by peculiar underground magmatic activity that the researchers can’t currently explain.
“I’m thoroughly confused by it,” says Clive Neal, an expert in lunar geology at the University of Notre Dame who was not involved with the new research.
by A. Watts, February 15, 2019 in WUWT
A provocative hypothetical question: What if the Moon was not there? Video follows.
This giant rock lights up the night and can even change colors. So what would we do without it? Would we all need night vision goggles? How would it affect the ocean tides? Our seasons? Or our sleep cycles? Or would the consequences be far more drastic?
As the closest celestial body to our planet, the moon exerts a gravitational pull that governs much of what happens here on Earth Take the sea, for example. If you like surfing, you can thank the moon when the moon’s gravitational pull tugs on our spinning Earth, the oceans respond, giving us high tides in some parts of the world, and low tides elsewhere.
by Anthony Watts, January 22, 2019 in WUWT
This is a treat. On Jan. 21st, a meteoroid slammed into the Moon. We know this because many amateur astronomers witnessed the explosion and recorded video and photos. The fireball was visible against the shadowy backdrop of a total lunar eclipse. Video of the event follows.
We know this because many amateur astronomers witnessed or photographed the explosion. Petr Horálek was one of them; he captured the fireball from Boa Vista, one of the islands of Cape Verde …
by Shaui Li et al., August 20, 2018 PNAS
We found direct and definitive evidence for surface-exposed water ice in the lunar polar regions. The abundance and distribution of ice on the Moon are distinct from those on other airless bodies in the inner solar system such as Mercury and Ceres, which may be associated with the unique formation and evolution process of our Moon. These ice deposits might be utilized as an in situ resource in future exploration of the Moon.