Scientists will soon have access to samples from a box of moon rocks that no one has opened since Neil Armstrong sealed it on the moon 50 years ago:
The upcoming experiments, on vacuum-sealed cores and a long-frozen rock, can be performed only once, at the precise moment the samples are opened. That’s why the materials have been held back since they were retrieved from the moon, said Ryan Zeigler, who curates the Apollo rocks collection. NASA was waiting for the right scientists, with the right technologies, at the right time.
With Apollo 11’s 50th anniversary this year and renewed interest in the moon ahead of a proposed return mission, Zeigler said, the right time is now.
Before the Apollo 11 mission, scientists couldn’t agree on where the moon came from. It’s a misfit in the solar system — much larger relative to its planet than almost any other moon. Some speculated that it was once an independent object that was “captured” by Earth’s gravity. Others proposed that the satellite formed in orbit alongside Earth when the planets were coalescing out of a primordial dust disc. Many grade-school textbooks taught that it was, in fact, a blob of Earth that had been flung away by our planet’s spin; the Pacific Ocean was thought to be a scar from this ancient loss.
All of those theories had to be discarded as soon as scientists saw the first Apollo rocks.
About 4.5 billion years ago, the theory goes, a long-gone giant planet called Theia, named for the mother of the Greek moon goddess, smashed into the newly formed Earth. The impact shattered both Theia and the proto-Earth and splashed millions of tons of material into space. Some of the rock coalesced in orbit around the Earth, and our satellite was born. The heaviest bits sank to the moon’s center, while the light minerals floated to the top of the worldwide magma ocean and crystallized, forming the thin anorthosite crust. The rocks and dust retrieved by Armstrong and Scott are relics of this long-ago tumult.
How cool! And how loony, in a sense. I can't wait to see whether they get evidence in support of the hypothesis.
The European Union Parliament today voted 410-192 to allow member states to end Daylight Saving Time in 2021:
The vote is not the last word on the issue but will form the basis of discussions with EU countries to produce a final law.
The countries have yet to take a stance.
A parliament report in favour of operating on a single time throughout the year said scientific studies link time changes to diseases of the cardiovascular or immune systems because they interrupt biological cycles, and that there were no longer any energy savings.
What this actually means requires one more EU-wide step:
All 28 member states would need to inform the European Commission of their choice ahead of the proposed switch, by April 2020. They would then coordinate with the bloc's executive so that their decisions do not disrupt the functioning of the single market.
Last year, the European Commission proposed abolishing the seasonal clock change after an EU-wide online poll showed overwhelming support. It has been accused, however, of rushing through the vote ahead of European Parliament elections in May.
Countries that wanted to be permanently on summertime would adjust their clocks for the final time on the last Sunday in March 2021. Those that opt for permanent wintertime would change their clocks for the final time on the last Sunday of October 2021.
The British government has yet to offer any formal opinion on the proposal, which risks creating fresh problems over the status of Northern Ireland after Brexit.
I think we can predict, just by looking at longitude, which countries will go which direction. The UK has made noises that it will keep the twice-yearly time changes, thank you very much. My guess is that Portugal, Spain, the Baltics, and other countries at the western ends of their time zones will opt for standard time, while other countries will go to summer time. That would prevent the problems I outlined when this measure first came into the news a few weeks ago.
I'm not going to link to any of the articles published in the last few days about how no one likes changing the clocks to and from Daylight Saving Time. Suffice to say, the debate hinges on two simple questions: how early do you want the sun to set, and how late do you want it to rise, in winter?
For a concrete example, if you live in Chicago, do you want the sun to rise at 7:19 or 8:19 on January 3rd (the latest of the year)? And if the sun rises at 8:19 that morning, is that an acceptable price to pay for the sun setting at 5:20 (instead of 4:20) on December 8th (the earliest of the year)?
A switch to year-long DST would mean that the sun would rise over Lake Michigan after 7am from October 12th until March 17th—five months of morning gloom, offset by the sun never setting before 5pm.
On the western edge of US time zones, the results would be truly weird. Just across Lake Michigan from Chicago is Benton Harbor, Mich. Year-long DST would make the earliest sunset there occur at 6:14pm. But the latest sunrise would be at 9:14am, with the sun rising after 9am from December 7th through January 31st, and the sun rising after 8am from October 17th through March 14th. After 7am? August 22nd through April 19th. Yes, permanent DST would relegate places like Western Michigan, Western Nebraska, and Idaho to nine months of gloomy mornings.
Ultimately I think this is why the permanent-DST proposals will go nowhere in the US. The parts of the US most sensitive to late sunrises (farming areas) will be the ones most affected.
And hey, won't Spain be fun when permanent DST comes to Europe in two years. The sleepy town of Pontevedra, Spain, on the west coast of that country and at about the same latitude as Chicago, will enjoy sunrises at 10:04am in January should Spain go permanently to UTC+2. (But hey, the sun will never set there before 7pm, so maybe that's a good trade-off?)
Of course, this is all about psychology. The sun rises and sets on its own; only our need to agree on time causes these odd artifacts. Maybe in western Spain they'll simply start work at noon? (Or, more likely, switch to UTC+1 year-round.)
The semi-annual Chicago Sunrise Chart is up. Enjoy.
The December solstice happens today at 22:21 UTC, which is 16:21 here in Chicago, which it turns out is the exact time of tonight's sunset. This is also true for everywhere along the lightest gray line on this map:
Note also that Africa and Europe will have a brilliant gibbous moon at the same time.
Journalist Kelly Weill, writing for the Daily Beast, went to a flat-earth convention:
Thousands of years after ancient Greeks began referencing Earth as a sphere in mathematical proofs, people who believe in a flat Earth have become a movement. They’ve found their voice in the disinformation age, fueled by YouTube videos. For true believers, it’s more than just a conspiracy theory. It’s whole world view, a level plane onto which hucksters, trolls, and Christian fundamentalists can insert their own ideologies.
In an age of rising conspiracy theories—voter fraud, QAnon, anti-vaxxers, chemtrails—Flat Earth might be the most foundational conspiracy theory of them all.
Religious conspiracy (some people I speak to at the conference accuse the Freemasons, not the Jews of covering up Flat Earth) and political uncertainty go hand in hand. Embittered by Germany’s loss in World War I, fascists falsely accused the country’s Jews of “stabbing Germany in the back” during the war. The conspiracy theory contributed to the Holocaust under Nazi rule. The ongoing genocide of the Rohingya, a Muslim minority in Myanmar, during a period of political strife has been fueled by a dramatic increase in anti-Rohingya hate speech and conspiracy on Facebook. In a period of political unrest in America, anti-Semitic conspiracy theories and subsequent murders of Jews are on the rise.
When the entire world feels uncertain, it’s no wonder people look for an easy culprit. Flat Earthers say the planet is a stationary disk that does not rotate or orbit the sun. But I speak to enough to suspect they still feel off-balance in the world.
I probably don't have to convince any regular readers of this blog of the (mostly) spherical shape of our home. But I have seen proof with my own eyes, and posted it here previously:
That is the shadow of the earth stretching straight out into space as the earth itself curves away under it. You, too, can see this any time you fly across the terminator, as thousands of people do daily.
Meanwhile, with a modern-day Know-Nothing party in control of our government, it seems almost natural that so many people would reject the only possible explanation for so many readily-observable phenomena in favor of something so insane it took a fantasy writer to describe it comprehensively. All hail the Great A'Tuin!
This morning's sunrise in Chicago, at 7:26, will be the latest until 6 November 2021. It is not the latest possible sunrise; that would be the one we'll have at 7:29 on 6 November 2027 (and had on 5 November 2016).
I do not really understand the law passed in 2007 that moved our return to standard time from October to November. Who wants to wake up before dawn? Not me.
Tomorrow the sun rises at 6:28. (I will probably do the same around 8.)
In the geocentric model of how things work, it's really easy for you to fall directly toward Earth. This happens because you are already moving fast enough to have a very small delta vee with the surface at any particular moment. Not so falling into the sun, which is so hard, we only just launched the first probe that can do it on purpose:
The reason has to do with orbital mechanics, the study of how natural forces influence the motions of rockets, satellites, and other space-bound technology. Falling into the sun might seem effortless since the star’s gravity is always tugging at everything in the solar system, including Earth. But Earth—along with all the other planets and their moons—is also orbiting the sun at great speed, which prevents it from succumbing to the sun’s pull.
This arrangement is great if you’d like to avoid falling into the sun yourself, but it’s rather inconvenient if you want to launch something there.
“To get to Mars, you only need to increase slightly your orbital speed. If you need to get to the sun, you basically have to completely slow down your current momentum,” says Yanping Guo, the mission-design and navigation manager for the Parker Solar Probe. Based at the Johns Hopkins Applied Physics Laboratory, Guo has been working on the probe for about 17 years.
Probes bound for deep-space destinations like Mars can piggyback off Earth’s momentum to fly faster. For a spacecraft to launch toward the sun, on the other hand, it must accelerate to nearly match the Earth’s velocity—in the opposite direction. With the planet’s motion essentially canceled out, the spacecraft can surrender to the sun’s gravity and begin to fall toward it. But this is almost impossible with current rocket technology, so spacecraft have to get some help, in the form of slingshot maneuvers off other planets, called gravity assists.
Douglas Adams, therefore, was partially correct: generally speaking, if you throw yourself at the sun, you will miss (and wind up in a stable orbit). NASA has just started the process of hitting it.
Astronomer Scott Sheppard has discovered 10 more moons orbiting Jupiter, bringing the gas giant's coterie up to 79:
Sheppard found them with the help of a ground-based telescope in Chile that had recently received an upgrade: a camera made for scanning the night sky for very faint objects. Sheppard was looking for Planet Nine, the planet some astronomers believe lurks somewhere at the edge of our solar system, jostling the orbits of other objects in strange ways. As the telescope gazed in the darkness way beyond Pluto, it ended up catching something much closer: a flurry of glinting, tiny objects near Jupiter, the smallest of which was about half a mile wide.
Sheppard couldn’t say whether these points of light were actually moons, at least not right away. To determine whether something is indeed a moon, astronomers must track the object for about a year to determine that, yes, its motions are governed by the gravitational tug of a planet. Sheppard says he couldn’t get excited about his findings in earnest until he observed the objects again a year later, this past spring, and his suspicions were confirmed.
If you came to this story expecting to find dazzling, close-up images of Jupiter’s newly discovered moons, we have some bad news: The era of discovering massive worlds around the gas planet ended more than 400 years ago, with Galileo. Like this latest batch, many of the moons astronomers have discovered around Jupiter in the past several decades have been smaller than cities. Their minuscule size has prompted some astronomers, including Sheppard and Williams, to wonder whether they should even bother giving them names. Williams says that discoverers of moons don’t have to name them if they don’t want to. Sheppard suggests perhaps it’s time to add another layer to our definition of a moon. “The definition of a moon is just anything that orbits a planet, so maybe once you start getting down to a kilometer or so in size, maybe we should start calling these things dwarf moons,” he says.
Now they just have to name all of them...