Voyager 1 Has Left the Solar System!


Today, it was announced that Voyager 1 has left the solar system for interstellar space.

It’s not the first time the announcement has been made.

In October 2012, it was thought the intrepid probe, first launched in September 1977, had blasted out of the heliosheath and left the solar system—until a couple of months later, when particles weren’t quite acting as scientists thought they should in a region that came to be called the “magnetic highway”—the outer boundary of the heliosphere, where the sun’s magnetic particles and those from interstellar space mingle, not unlike a two-lane highway.

Scientists had thought two things would happen when Voyager officially left the solar system: That the solar winds would fade to nothing (which happened), and that the magnetic fields of the region would change direction marking the end of the sun’s influence. That one didn’t happen.

In recent months some scientists have been reassessing the data and saying “Yes, it might have left the solar system after all.” Now, NASA has confirmed that.

The whole debate was enough of a headache to get a nice ribbing from former JPL employee turned XKCD cartoonist Randall Munroe.

The Future of Interstellar Space Travel

Voyager 1 is now the first craft to officially leave the solar system, pacing along at 38,610 miles per hour. Others are set to follow.

Voyager 1's sister craft, Voyager 2, is not yet beyond the solar system, but is just a few years behind, traveling at a more sluggish crawl of around 35,000 MPH.

Two other probes, Pioneer 10 and 11, will also leave the solar system someday. Pioneer 10 was reported to have left by the New York Times in 1983except it was just past the orbit of Neptune at the time. Pioneer 11 accomplished this feat in 1990. But as the Voyagers have revealed, that is far, far shy of the end of the solar system.

Currently, Voyager 1 is more than 125 times the distance (called an AU, or astronomical unit) from the Earth to the Sun. Pioneer 10 is far behind that, projected at 109 AU in 2012. Communication was lost in 2003. Voyager 2 is still active, and is approximately 103 AU out. Pioneer 11, which NASA lost contact with in 1995, is estimated to be at 86 AU as of 2012.

We’d of course be remiss not to mention New Horizons, the craft currently on a trajectory for Pluto, which it will swoop by in 2015 before continuing on to the outer solar system. Thus far, it’s only about 27 AU out from the sun. It is expected to leave the solar system in 2029. A booster rocket of the craft is also on a path set to exit the solar system.

Little Green Men

With some push from Carl Sagan, both Voyager probes were given a “Golden Record,” a phonograph of words and images meant to tell aliens of existence here on earth, should the probes be found. Classical music melds with sounds of nature and a series of hellos in various languages on the disc.

Included in the music selections? “Johnny B. Goode” by Chuck Berry.

The Pioneers contain simple plaques, showing two naked humans, the position of the solar system in relation to a group of stars, and the location of the Earth within the solar system. (Prior to Pluto’s demotion, of course.)

Speaking of Pluto, New Horizons doesn’t have an equivalent to either on board. There are a few objects on board, though, which might pique the interest of the discoverers, even if they’ll have no way to tell what they are. Included is a CD with the names of 400,000 persons, as well as the ashes of Clyde Tombaugh, the astronomer who first discovered Pluto in 1930. A Florida state quarter and a scrap of SpaceShipOne are among the few other personal effects on the craft.

Today's Wine Glasses Are Almost Seven Times Larger Than They Were in 1700

Holiday party season (a.k.a. hangover season) is in full swing. While you likely have no one to blame but yourself for drinking that second (or third) pour at the office soiree, your glassware isn't doing you any favors—especially if you live in the UK. Vino vessels in England are nearly seven times larger today than they were in 1700, according to a new study spotted by Live Science. These findings were recently published in the English medical journal The BMJ.

Researchers at the University of Cambridge measured more than 400 wineglasses from the past three centuries to gauge whether glass size affects how much we drink. They dug deep into the history of parties past, perusing both the collections of the Ashmolean Museum of Art and Archaeology at the University of Oxford and the Royal Household's assemblage of glassware (a new set is commissioned for each monarch). They also scoured a vintage catalog, a modern department store, and eBay for examples.

After measuring these cups, researchers concluded that the average wineglass in 1700 held just 2.2 fluid ounces. For comparison's sake, that's the size of a double shot at a bar. Glasses today hold an average of 15.2 fluid ounces, even though a standard single serving size of wine is just 5 ounces.

BMJ infographic detailing increases in wine glass size from 1700 to 2017
BMJ Publishing group Ltd.

Advances in technology and manufacturing are partly to blame for this increase, as is the wine industry. Marketing campaigns promoted the beverage as it increasingly became more affordable and available for purchase, which in turn prompted aficionados to opt for larger pours. Perhaps not surprisingly, this bigger-is-better mindset was also compounded by American drinking habits: Extra-large wineglasses became popular in the U.S. in the 1990s, prompting overseas manufacturers to follow suit.

Wine consumption in both England and America has risen dramatically since the 1960s [PDF]. Cambridge researchers noted that their study doesn't necessarily prove that the rise of super-sized glassware has led to this increase. But their findings do fit a larger trend: previous studies have found that larger plate size can increase food consumption. This might be because they skew our sense of perception, making us think we're consuming less than we actually are. And in the case of wine, in particular, oversized glasses could also heighten our sensory enjoyment, as they might release more of the drink's aroma.

“We cannot infer that the increase in glass size and the rise in wine consumption in England are causally linked,” the study's authors wrote. “Nor can we infer that reducing glass size would cut drinking. Our observation of increasing size does, however, draw attention to wine glass size as an area to investigate further in the context of population health.”

[h/t Live Science]

Researchers Pore Over the Physics Behind the Layered Latte

The layered latte isn't the most widely known espresso drink on coffee-shop menus, but it is a scientific curiosity. Instead of a traditional latte, where steamed milk is poured into a shot (or several) of espresso, the layered latte is made by pouring the espresso into a glass of hot milk. The result is an Instagram-friendly drink that features a gradient of milky coffee colors from pure white on the bottom to dark brown on the top. The effect is odd enough that Princeton University researchers decided to explore the fluid dynamics that make it happen, as The New York Times reports.

In a new study in Nature Communications, Princeton engineering professor Howard Stone and his team explore just what creates the distinct horizontal layers pattern of layered latte. To find out, they injected warm, dyed water into a tank filled with warm salt water, mimicking the process of pouring low-density espresso into higher-density steamed milk.

Four different images of a latte forming layers over time
Xue et al., Nature Communications (2017)

According to the study, the layered look of the latte forms over the course of minutes, and can last for "tens of minutes, or even several hours" if the drink isn't stirred. When the espresso-like dyed water was injected into the salt brine, the downward jet of the dyed water floated up to the top of the tank, because the buoyant force of the low-density liquid encountering the higher-density brine forced it upward. The layers become more visible when the hot drink cools down.

The New York Times explains it succinctly:

When the liquids try to mix, layered patterns form as gradients in temperature cause a portion of the liquid to heat up, become lighter and rise, while another, denser portion sinks. This gives rise to convection cells that trap mixtures of similar densities within layers.

This structure can withstand gentle movement, such as a light stirring or sipping, and can stay stable for as long as a day or more. The layers don't disappear until the liquids cool down to room temperature.

But before you go trying to experiment with layering your own lattes, know that it can be trickier than the study—which refers to the process as "haphazardly pouring espresso into a glass of warm milk"—makes it sound. You may need to experiment several times with the speed and height of your pour and the ratio of espresso to milk before you get the look just right.

[h/t The New York Times]


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