- China's lunar rover is outfitted with cameras and other equipment designed to collect data from a crater near the moon's southern pole.
- Studying the far side of the moon could provide scientists with a better understanding of what gave rise to the conditions necessary for life on Earth.
- In addition to scientific discoveries, China also likely plans to use the data from its mission to better plan future mining operations.
China successfully landed a spacecraft on the far side of the moon on Wednesday, marking a world first that comes just 16 years after the nation launched its first astronaut into space.
Speaking with China Global Television Network, a state-operated English TV channel, spaceflight expert Yang Yuguang, who is affiliated with the China Aerospace Science & Industry Corporation, said the new feat is "a milestone" for the nation's lunar exploration project.
In the United States, NASA Administrator Jim Bridenstine called the landing "an impressive accomplishment" on Twitter.
The unmanned spacecraft, dubbed the Chang'e 4, is carrying a 300-pound rover that's designed to use cameras, ground-penetrating radar and spectrometers to collect data from the lunar surface, particularly from the Von Kármán crater, the oldest and deepest on the moon. This crater lies in the South Pole-Aitken Basin, a 1,600-mile-wide impact crater that was likely formed when a massive asteroid collided with the moon and brought some material from its upper mantle to the surface.
China's mission control are expected to ensure the rover is operating effectively before attempting to collect data. China, whose burgeoning space program launched more rockets into orbit than any other nation in 2018, hopes to use its rover to learn more about the origins and evolution of the moon. In coming years, the Chang'e 5 and 6 missions are scheduled to retrieve lunar samples and bring them back to Earth.
Why can't we see the far side of the moon?
The answer isn't because the moon doesn't rotate — it does — but rather because the moon's rotational period matches its orbital period around the Earth. In other words, the moon takes about 27 days to orbit our planet once, and during that same time period the moon also rotates around its own axis exactly once. So, only one side of the moon ever faces Earth.
(By the way, calling it the "dark side of the moon" isn't accurate because the far side of the moon gets plenty of sunlight.)
Interestingly, the moon and the Earth weren't always in synch with each other. But over billions of years, the pull of Earth's gravity actually changed the shape of the moon, forming slight bulges in some places. Now, these bulges help keep the moon oriented toward our planet at all times. What's more, the moon's gravity also exerts itself on the Earth, causing ocean tides to shift as the Earth rotates.
In 1959, humans caught the first glimpse of the far side of the moon after the Soviet spacecraft Luna 3 snapped a couple dozen photographs in a landmark mission.
Photos from Luna 3
The images proved what many scientists had hypothesized: The far side of the moon looks very different from the side we always see because it's been bombarded by countless asteroids over the eons, a result of constantly facing the cosmos.
During the Apollo 8 mission in 1968, NASA astronaut Bill Anders described the far of the moon to mission control:
The backside looks like a sand pile my kids have been playing in for a long time... It's all beat-up, no definition... Just a lot of bumps and holes.
Here's a more recent photo of the far side of the moon, taken by NASA's Lunar Reconnaissance Orbiter in 2011.
Why study the far side of the moon?
One goal of China's mission to determine approximately when the South Pole-Aitken Basin was created. Interestingly, the bombardment of the southern region of the moon by asteroids seems to have occurred around the same time life appeared on Earth. This might give scientists clues about what creates the conditions for life on planets.
"Understanding the intensity and timing of the bombardment is important as… that was going on about the same time that life appeared on Earth," Ian Crawford, professor of planetary science and astrobiology at Birkbeck University, London, told The Guardian. "The Earth has lost its record of that very early time."
In addition to studying the basin, China's lander will also conduct a biology experiment that will see whether plant seeds will germinate and silkworm eggs will hatch in the moon's low gravity. Outside of science, China likely has other motivations: collecting data for future mining operations.
"This is a major achievement technically and symbolically," Namrata Goswami, an independent analyst who wrote about space for the Defense Department's Minerva Research Institute, told the New York Times. "China views this landing as just a stepping stone, as it also views its future manned lunar landing, since its long-term goal is to colonize the moon and use it as a vast supply of energy."
- Before the hurricane season even started in 2020, Arthur and Bertha had already blown through, and Cristobal may be brewing right now.
- Weather forecasters see signs of a rough season ahead, with just a couple of reasons why maybe not.
- Where's an El Niño when you need one?
Welcome to Hurricane Season 2020. 2020, of course, scoffs at this calendric event much as it has everything else that's normal — meteorologists have already used up the year's A and B storm names before we even got here. And while early storms don't necessarily mean a bruising season ahead, forecasters expect an active season this year. Maybe storms will blow away the murder hornets and 13-year locusts we had planned.
NOAA expects a busy season
According to NOAA's Climate Prediction Center, an agency of the National Weather Service, there's a 60 percent chance that we're embarking upon a season with more storms than normal. There does, however, remain a 30 percent it'll be normal. Better than usual? Unlikely: Just a 10 percent chance.
Where a normal hurricane season has an average of 12 named storms, 6 of which become hurricanes and 3 of which are major hurricanes, the Climate Prediction Center reckons we're on track for 13 to 29 storms, 6 to 10 of which will become hurricanes, and 3 to 6 of these will be category 3, 4, or 5, packing winds of 111 mph or higher.
What has forecasters concerned are two factors in particular.
This year's El Niño ("Little Boy") looks to be more of a La Niña ("Little Girl"). The two conditions are part of what's called the El Niño-Southern Oscillation (ENSO) cycle, which describes temperature fluctuations between the ocean and atmosphere in the east-central Equatorial Pacific. With an El Niño, waters in the Pacific are unusually warm, whereas a La Niña means unusually cool waters. NOAA says that an El Niño can suppress hurricane formation in the Atlantic, and this year that mitigating effect is unlikely to be present.
Second, current conditions in the Atlantic and Caribbean suggest a fertile hurricane environment:
- The ocean there is warmer than usual.
- There's reduced vertical wind shear.
- Atlantic tropical trade winds are weak.
- There have been strong West African monsoons this year.
Here's NOAA's video laying out their forecast:
But wait.
ArsTechnica spoke to hurricane scientist Phil Klotzbach, who agrees generally with NOAA, saying, "All in all, signs are certainly pointing towards an active season." Still, he notes a couple of signals that contradict that worrying outlook.
First off, Klotzbach notes that the surest sign of a rough hurricane season is when its earliest storms form in the deep tropics south of 25°N and east of the Lesser Antilles. "When you get storm formations here prior to June 1, it's typically a harbinger of an extremely active season." Fortunately, this year's hurricanes Arthur and Bertha, as well as the maybe-imminent Cristobal, formed outside this region. So there's that.
Second, Klotzbach notes that the correlation between early storm activity and a season's number of storms and intensities, is actually slightly negative. So while statistical connections aren't strongly predictive, there's at least some reason to think these early storms may augur an easy season ahead.
Image source: NOAA
Batten down the hatches early
If 2020's taught us anything, it's how to juggle multiple crises at once, and layering an active hurricane season on top of SARS-CoV-2 — not to mention everything else — poses a special challenge. Warns Treasury Secretary Wilbur Ross, "As Americans focus their attention on a safe and healthy reopening of our country, it remains critically important that we also remember to make the necessary preparations for the upcoming hurricane season." If, as many medical experts expect, we're forced back into quarantine by additional coronavirus waves, the oceanic waves slamming against our shores will best be met by storm preparations put in place in a less last-minute fashion than usual.
Ross adds, "Just as in years past, NOAA experts will stay ahead of developing hurricanes and tropical storms and provide the forecasts and warnings we depend on to stay safe."
Let's hope this, at least, can be counted on in this crazy year.
