In 2009, NASA launched the Lunar Reconnaissance Orbiter (LRO), the first mission to be sent by the US to the Moon in over a decade. Once there, the LRO conducted observations that led to some profound discoveries. For instance, in a series of permanently-shaded craters around the Moon’s South Pole-Aitken Basin, the probe confirmed the existence of abundant water ice.
On May 20th, 2018, the China National Space Agency (CNSA) launched the Queqiao spacecraft, the vehicle that would deliver the Chang’e-4mission to the Moon. This vehicle was also responsible for transporting a lesser-known mission to the Moon, known as the Longjiang twin spacecraft. This package consisted of two satellites designed to fly in formation and validate technologies for low-frequency radio astronomy.
While Queqiao flew beyond the Moon to act as a communications relay for the Chang’e-4 lander, the Longjiang satellites were to enter orbit around the moon. On July 31st, 2019, after more than a year in operation, the Longjiang-2 satellite deorbited crashed on the lunar surface. And thanks to efforts spacecraft tracker Daniel Estévez and his colleagues, the Lunar Reconnaissance Orbiter (LRO) was able to photograph the impact site.
This image of the lunar highlands is from NASA’s Lunar Reconnaissance Orbiter. You’d need superhuman eyesight to spot it, but India’s crashed Vikram lander is in there somewhere. The lander attempted to land on the Moon on September 6th, but when it was only 2.1 km above the surface, within reach of its objective, ISRO (Indian Space Research Organization) lost contact with the spacecraft.
In addition to being the only solvent that is capable of supporting life, water is essential to life as we know it here on Earth. Because of this, finding deposits of water – whether in liquid form or as ice – on other planets is always exciting. Even where is not seen as a potential indication of life, the presence of water offers opportunities for exploration, scientific study, and even the creation of human outposts.
This has certainly been the case as far as the Moon and Mercury are concerned, where water ice was discovered in the permanently-shadowed cratered regions around the poles. But according to a new analysis of the data from the Lunar Reconnaissance Orbiter and the MESSENGER spacecraft, the Moon and Mercury may have significantly more water ice than previously thought.
The history of the Moon is a tale told by geology, apparent in its rocks, craters, and other surface features. For centuries, astronomers have studied the Moon from afar and for the past few decades, it has been visited by countless robotic missions. Between 1969 and 1972, a total of twelve astronauts walked on its surface, conducted lunar science, and brought samples of lunar rock back to Earth for study.
These efforts have taught us a lot about the things that have shaped the lunar surface, be they one-off events like the massive impact that formed the Shakleton crater to things that happened regularly throughout its 4.51 billion-year history. For instance, scientists recently discovered something unusual about the Antoniadi crater: a large boulder was perched on the rim of a smaller crater within after rolling about 1000 meters (1093 yards) downhill.
It’s always easier to show someone a picture of something rather than to use 1,000 words to explain it. The people at NASA’s Scientific Visualization Studio (SVS) know this, and they’re experts. Every year they release a simulation of the Moon that shows what the Moon will look like to us each day.
NASA’s Moon simulator uses images and data captured by the Lunar Reconnaissance Orbiter (LRO) to recreate the Moon on each hour of each day of each month in 2018. You can input any date and time to view the Moon (Dial-a-Moon) as it will appear at that time. You can also watch a video of the Moon over the course of the entire year. Along the way, you might learn something.
We often hear how the Moon’s appearance hasn’t changed in millions or even billions of years. While micrometeorites, cosmic rays and the solar wind slowly grind down lunar rocks, the Moon lacks erosional processes such as water, wind and lurching tectonic plates that can get the job done in a hurry.
Remember Buzz Aldrin’s photo of his boot print in the lunar regolith? It was thought the impression would last up to 2 million years. Now it seems that estimate may have to be revised based on photos taken by the Lunar Reconnaissance Orbiter (LRO) that reveal that impacts are transforming the surface much faster than previously thought.
The LRO’s high resolution camera, which can resolve features down to about 3 feet (1-meter) across, has been peering down at the Moon from orbit since 2009. Taking before and after images, called temporal pairs, scientists have identified 222 impact craters that formed over the past 7 years. The new craters range from 10 feet up to 141 feet (3-43 meters) in diameter.
By analyzing the number of new craters and their size, and the time between each temporal pair, a team of scientists from Arizona State University and Cornell estimated the current cratering rate on the Moon. The result, published in Nature this week, was unexpected: 33% more new craters with diameters of at least 30 feet (10 meters) were found than anticipated by previous cratering models.
Similar to the crater that appeared on March 17, 2013 (above), the team also found that new impacts are surrounded by light and dark reflectance patterns related to material ejected during crater formation. Many of the larger impact craters show up to four distinct bright or dark reflectance zones. Nearest to the impact site, there are usually zone of both high and low reflectance. These two zones likely formed as a layer of material that was ejected from the crater during the impact shot outward to about 2½ crater diameters from the rim.
From analyzing multiple impact sites, far flung ejecta patterns wrap around small obstacles like hills and crater rims, indicating the material was traveling nearly parallel to the ground. This kind of path is only possible if the material was ejected at very high speed around 10 miles per second or 36,000 miles per hour! The jet contains vaporized and molten rock that disturb the upper layer of lunar regolith, modifying its reflectance properties.
How LRO creates temporal pairs and scientists use them to discover changes on the moon’s surface.
In addition to discovering impact craters and their fascinating ejecta patterns, the scientists also observed a large number of small surface changes they call ‘splotches’ most likely caused by small, secondary impacts. Dense clusters of these splotches are found around new impact sites suggesting they may be secondary surface changes caused by material thrown out from a nearby primary impact. From 14,000 temporal pairs, the group identified over 47,000 splotches so far.
Based on estimates of size, depth and frequency of formation, the group estimated that the relentless churning caused by meteoroid impacts will turn over 99% of the lunar surface after about 81,000 years. Keep in mind, we’re talking about the upper regolith, not whole craters and mountain ranges. That’s more than 100 times faster than previous models that only took micrometeorites into account. Instead of millions of years for those astronaut boot prints and rover tracks to disappear, it now appears that they’ll be wiped clean in just tens of thousands!
Everyone on Earth is invited to join the celebration by hosting or attending an InOMN event — and uniting on one day each year to look at and learn about the Moon together. We encourage you to go to InOMN events near you, such as at your local planetariums or museums, or to go out and observe the moon yourself! You can find events near you at the InOMN site. You can also follow the InOMN Twitter feed to see what everyone is doing to celebrate!
Our friends over at CosmoQuest are proud to be partners in this celebration of Earth’s natural satellite. There you can “Observe the Moon” all year long by taking part in lunar-themed activities, such as our Moon Mappers citizen science program, where you’ll get to look at some of the most detailed images taken by the LRO, and help our scientists study the moon and it’s surface. This excellent program is available free of charge, no matter the weather, time of day or your location – you get the best views of the Moon ever!
Take some photos of your activities, whether outdoors observing or indoors mapping craters, and share them online at the CosmoQuest Twitter and Facebook feeds using the hashtag #observethemoon, and CosmoQuest will repost their favorites!
Here are just a few of the media celebrations that have already been posted for InOMN!
“The Moon and More” is a music video starring musicians Javier Colon (Season 1 winner of NBC’s “The Voice”), and Matt Cusson in collaboration with NASA’s Goddard Space Flight Center and the Lunar Reconnaissance Orbiter (LRO) mission.
Credits: NASA’s Goddard Space Flight Center/David Ladd, producer
For years, scientists have been hunting for the stable lava tubes that are believed to exist on the Moon. A remnant from the Moon’s past, when it was still volcanically active, these underground channels could very well be an ideal location for lunar colonies someday. Not only would their thick roofs provide naturally shielding from solar radiation, meteoric impacts, and extremes in temperature. They could also be pressurized to create a breathable environment.
But until now, evidence of their existence has been inferred from surface features such as sinuous rilles – channel-like depressions that run along the surface that indicate the presence of subterranean lava flows – and holes in the surface (aka. “skylights”). However, recent evidence presented at the 47th Lunar and Planetary Science Conference (LPSC) in Texas indicates that one such stable lava tube could exist in the once-active region known as Marius Hills.
NASA has just received a significant boost in the agency’s current budget after both chambers of Congress passed the $1.1 Trillion 2016 omnibus spending bill this morning, Friday, Dec. 18, which funds the US government through the remainder of Fiscal Year 2016.