Astronomy Picture of the Day: Saturns Iapetus: Painted Moon


Saturns Iapetus: Painted Moon
What has happened to Saturn's moon Iapetus? Vast sections of this strange world are dark as coal, while others are as bright as ice. The composition of the dark material is unknown, but infrared spectra indicate that it possibly contains some dark form of carbon. Iapetus also has an unusual equatorial ridge that makes it appear like a walnut. To help better understand this seemingly painted moon, NASA directed the robotic Cassini spacecraft orbiting Saturn to swoop within 2,00 0 kilometers in 2007. Pictured here, from about 75,000 kilometers out, Cassini's trajectory allowed unprecedented imaging of the hemisphere of Iapetus that is always trailing. A huge impact crater seen in the south spans a tremendous 450 kilometers and appears superposed on an older crater of similar size. The dark material is seen increasingly coating the easternmost part of Iapetus, darkening craters and highlands alike. Close inspection indicates that the dark coating typically faces the moon's equator and is less than a meter thick. A leading hypothesis is that the dark material is mostly dirt leftover when relatively warm but dirty ice sublimates. An initial coating of dark material may have been effectively painted on by the accretion of meteor-liberated debris from other moons.

June 03, 2018
via NASA https://ift.tt/2xCjmp1
Space

Manage this Applet


Unsubscribe from these notifications or sign in to manage your Email Applets.

IFTTT

Comments

Post a Comment

Popular posts from this blog

Evernote cuts staff as user growth stalls

Image
Note-taking app Evernote has fallen on hard times of late, culminating in its latest spate of job cuts impacting 15 percent of its workforce (54 employees). CEO Chris O' Neil -- an ex-Googler who took the reins in 2015 -- announced the firings at an all-hands meeting earlier today, reports TechCrunch . In a message on the Evernote blog , O' Neill admitted he'd set "incredibly aggressive goals" for the company in 2018. He continued: "Going forward, we are streamlining certain functions, like sales, so we can continue to speed up and scale others, like product development and engineering." The layoffs follow an exec exodus just weeks ago and the company's recent brand refresh (complete with a refined logo and wordmark). But critics are more concerned about its product, especially the free tier, which they claim lacks the perks to...
Read more

The best air conditioner

Image
By Liam McCabe This post was done in partnership with Wirecutter . When readers choose to buy Wirecutter's independently chosen editorial picks, it may earn affiliate commissions that support its work. Read the full article here . After six summers of researching, testing, and recommending window air conditioners, we've learned that quiet and affordable ACs make most people the happiest—and we think the LG LW8016ER will fit the bill in most rooms. This 8,000 Btu unit cools as efficiently and effectively as any model with an equal Btu rating, and runs at a lower volume and deeper pitch than others at this price. Little extra features like a fresh-air vent, two-axis fan blades, and a removable drain plug help set it apart, too. The LG LW8016ER is a top choice for an office or den, and some people will find it quiet enough for a bedroom, too. If our main pic...
Read more

We won't see a 'universal' vape oil cartridge anytime soon

Image
Pre-loaded cartridges of cannabis concentrate are currently among the most popular means of consumption, and for good reason. They're discreet to use and easy to handle, a far cry from the dark days of 2016 when we had to dribble hash oil or load wax into narrow-mouthed vape pens by hand. But, frustratingly, an ever increasing number of oil cartridge manufacturers employ one-off design standards so that their products won't work with those of their competitors, thereby locking customers into proprietary ecosystems. We've already seen this with nicotine vaporizers -- which has a seen a massive rise in "pod systems" in the last few years, each outfitted with a unique canister and battery built to be incompatible with those of their competition. Is it too late for the burgeoning cannabis industry to set a universal standard for their product designs? ...
Read more