Titan (Saturn's moon)

The Start of Cassini’s Grand Finale

Cue drumroll…

For the first time ever, our Cassini spacecraft dove through the narrow gap between Saturn and its rings on April 26. At 5 a.m. EDT, Cassini crossed the ring plane with its science instruments turned on and collecting data. 

During this dive, the spacecraft was not in contact with Earth. The first opportunity to regain contact with the spacecraft is expected around 3 a.m. EDT on April 27.

This area between Saturn and its rings has never been explored by a spacecraft before. What we learn from these daring final orbits will further our understanding of how giant planets, and planetary systems everywhere, form and evolve.

So, you might be asking…how did this spacecraft maneuver its orbit between Saturn and its rings? Well…let us explain!

On April 22, Cassini made its 127th and final close approach to Saturn’s moon Titan. The flyby put the spacecraft on course for its dramatic last act, known as the Grand Finale. 

As the spacecraft passed over Titan, the moon’s gravity bent its path, reshaping the robotic probe’s orbit slightly so that instead of passing just outside Saturn’s main rings, Cassini would begin a series of 22 dives between the rings and the planet.

With this assist, Cassini received a large increase in velocity of approximately 1,925 mph with respect to Saturn.

This final chapter of exploration and discovery is in many ways like a brand-new mission. Twenty-two times, the Cassini spacecraft will dive through the unexplored space between Saturn and its rings. What we learn from these ultra-close passes over the planet could be some of the most exciting revelations ever returned by the long-lived spacecraft.

Throughout these daring maneuvers, updates will be posted on social media at:

@CassiniSaturn on Twitter
@NASAJPL on Twitter

Updates will also be available online at: https://saturn.jpl.nasa.gov/mission/grand-finale/milestones/ 

Follow along with us during this mission’s Grand Finale!

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Solar System: Things to Know This Week

We’ve been up close and personal with Saturn for 13 years now, thanks to the Cassini mission

From a tour of Saturn’s many enthralling moons to an incredible view of Earth through its rings, the planet continues to captivate the imagination. This week, here are 10 things you need to know about our fascinating ringed neighbor.

1. Strange Sighting

When Galileo Galilei was observing Saturn in the 1600s, he noticed strange objects on each side of the planet. He drew in his notes a triple-bodied planet system with ears. These “ears” were later discovered to be the rings of Saturn.

2. Solar System Status

Saturn orbits our sun and is the sixth planet from the sun at an average distance of about 886 million miles or 9.5 AU.

3. Short Days

Time flies when you’re on Saturn. One day on Saturn takes just 10.7 hours (the time it takes for Saturn to rotate or spin once). The planet makes a complete orbit around the sun (a year in Saturnian time) in 29 Earth years, or 10,756 Earth days. saturn.jpl.nasa.gov/news/2955/measuring-a-day

4. No Shoes Necessary

That’s because you can’t stand on Saturn—it’s a gas-giant planet and doesn’t have a solid surface. But you might want a jacket. The planet’s temperatures can dip to -220 degrees F.

5. Few visitors

Only a handful of missions have made their way to Saturn: Pioneer 11, Voyager 1 and 2, and Cassini-Huygens, which is there now. Since 2004, Cassini has been exploring Saturn and its moons and rings—but will complete its journey on Sept. 15, 2017.

6. Saturn’s Close-Up

This month is a great time to observe Saturn from Earth. Check out June’s “What’s Up?” video for a how-to guide.

7. Daring Dives

Saturn’s spectacular ring system is made up of seven rings with several gaps and divisions between them. From now until September, the Cassini spacecraft is performing a set of daring dives every week between the planet and the rings. No other mission has ever explored this unique region before, and what we learn from these final orbits will help us understand of how giant planets—and planetary systems everywhere—form and evolve.

8. Many, Many Moons 

Saturn has a total of 62 moons: 53 known moons, with an additional nine moons awaiting confirmation.

9. Curious Shapes 

Saturn’s moon Atlas looks like a flying saucer. See for yourself.

10. Would You Live on a Moon? 

Saturn can’t support life as we know it, but some of its moons have conditions that might support life. Ocean worlds could be the answer to life in space and two of Saturn’s moons—Titan and Enceladus—are on that list.

Want to learn more? Read our full list of the 10 things to know this week about the solar system HERE.

Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com

Full Moon and Jupiter sharing a field of view. 

Labeled top to bottom, the tiny pinpricks of light above bright Jupiter are the four Galilean moons; Callisto, Europa, Ganymede, and Io. Callisto, Ganymede, and Io are physically larger than Earth’s Moon, while water world Europa is only slightly smaller. In fact, of the Solar System’s six largest planetary satellites, only Saturn’s moon Titan is missing from the scene.

Image Credit & Copyright: Göran Strand

5

Destiny 2 Destinations

[In order pictured…]

The Last City, Earth

The City is the last populated city on Earth and the last bastion for mankind and civilization. The City was built after The Traveler arrived and is located directly below where The Traveler hovers. Mankind came together to build The City underneath the Traveler because it provides powers and protection to humankind.


European Dead Zone (EDZ), Earth

European Dead Zone was ground-zero for a cataclysmic event that left a massive shard of The Traveler – the source of every Guardian’s power and immortality – embedded into the vast landscape. For years, only wild vegetation and the remains of an abandoned city were evidence of our forgotten past. Now, the Red Legion are using the European Dead Zone as a staging ground for their war machine.


Titan, Moon of Saturn

The great monuments of mankind’s utopian Golden Age now lie toppled or half-submerged within the rolling ocean that blankets the entire surface of Titan. All that remains is a flotilla of construction barges and a lone human habitat that serves as the perfect hiding place for some of humanity’s scattered forces – and something far more sinister below.


Nessus, Vex Planetoid

Lush with giant twisted trees, deep caverns, waterfalls, and silver swamps, the origin of this planetoid remains unknown. What is clear is that the Vex have nearly transformed the entire planetoid into a machine world, above and below the surface. For those Guardians willing to brave the dangers and explore the myriad of mysteries, treasures beyond the imagination await.


Io, Moon of Jupiter

Io was the last place visited by The Traveler, and the site of great interest to both humanity and the timeless Vex machines. The Red Legion, too, now seek to unravel the secrets and power of this place, gouging at the surface, seeking to uncover new sources of power to aid in their quest to dominate our worlds. It is up to you to protect this place, and to preserve its great legacy.

Destiny 2: Live Reveal Highlights

Highlights

  • more approachable, all the game types will be open to everyone and they’ve made it easier to find people to play with
  • enhanced the solo experience overall
  • the environments look awesome
  • more story quests
  • really nice campaign cinematics (and a good number of them apparently)
  • all new armor and weapons
  • “more to do in D2 than any game we’ve ever made at Bungie”
  • campaign will take you across the system and to new places, with missions, and cinematics
  • Strikes (co-op missions)
  • Crucible (PvP competitive multi; 4v4 vs for all game modes, new HUD stuff like knowing when teammates have their supers; sounds familiar lol
  • new game type called Countdown attack/defend mode game type for Crucible
  • Raids: they’re back but they didn’t tell us anything about the new one yet
  • launch all activities from the world without going to orbit (unlike D1)
  • World: ambient encounters, chests to find, patrols; adventures: treasure maps, lost sectors to discover
  • new characters with side quests that offer these different adventures
  • game map; jump to any planet from your map 
  • public events in the world
  • 4 new worlds
    •  European dead zone (on earth): largest new location. Looks amazing. 
    • Titan: moon of Saturn, ocean planet with structures built on stilts basically
      • Nessus: alien planet, unique plants/animal
      • Io: Jupiter moon, bunch of lore/mythology regarding the Traveller
  • Clans will be an officially supported feature: makes it easier playing with people; in-game rosters, tools to build fireteams, and custom banners; 
  • Clan reward system: no matter what you do when, it works towards earning rewards for whole clan
  • Guided Games: clans and solo players can meet; solo players can PICK a clan to join temporarily for a co-op game mode
    • guided games can also be helpful for clans: opens up party to solo players to fill empty slots for co-op missions

PC News!!

  • Some additional features for PC (probably enhanced graphics/graphics options)
  • Available exclusively through Blizzard’s Battle.net


Overall, in Destiny 2, Bungie has put an emphasis on storytelling, friendship & community, and exploring the universe at your own pace.

just-some-writer  asked:

I have a world in my novel that being investigated for terraformation. It's a large moon (slightly smaller than Earth) orbiting a gas giant. It's tidal-locked to its planet. Would the planet-facing hemisphere have a different climate than the non-planet-facing hemisphere? I currently have it written that the outward-facing side is more temperate, while the other is much warmer. But that just struck me as a fun idea and I don't actually want to use it if it's weird or implausible. Thanks!

Note: the following is for the moon to support life-as-we-know-it (carbon-based, some type of DNA or analogue, etc). Silicon-based life or other exotic life could live in very different environs..

A habitable moon orbiting a gas giant (which we will call the primary) would require both the gas giant primary and the habitable moon to have certain characteristics.

For analysis, lets assume the primary is a Jupiter-sized gas giant. We’d have to move it closer to it’s star than Jupiter is in our system, so there would be enough heat from the star to keep the planet habitable. The additional heat from the primary will help so we don’t have to move it as close to the star as we otherwise might.

This would make your primary a ‘hot Jupiter’ - a gas giant that orbits close to it’s star. We know of a lot of hot Jupiters in nearby systems.

Having an Earth-sized moon isn’t a stretch at all. The second largest moon in our Solar system is Titan, a moon of Saturn. It has a radius of 2575 km, about half the size of the Earth. It also has an atmosphere - one made of nitrogen, methane, and hydrogen. Ick, but this shows that a large moon with an atmosphere is possible.

The biggest danger to your habitable moon is the primary’s magnetosphere. This is the magnetic field generated by the primary. Although this magnetic field will help shield your moon from cosmic rays and radiation from its star, it also traps a lot of radiation particles and keeps them close to the primary - like Earth’s Van Allen Belts but much, much bigger and powerful. On moons close to the primary, that’s enough radiation to kill everything. Jupiter’s inner moons are orbiting inside a giant microwave oven.

To have a life-bearing moon, we need to do one of two things to it - preferably both to be on the safe side: move the moon outside of the radiation belts of the magnetosphere and/or give the moon it’s own magnetic field.

As your moon is about Earth-sized, it probably has a rotating iron core. It’ll have a magnetic field, but lets place it outside the primary’s radiation danger zone just to make sure.

For Jupiter, the safe distance is about 1.5 million km. So, lets put your moon at the orbit of Callisto at 1.8 million km. At this distance, what little radiation your moon gets from the primary’s belts is blocked by the moon’s magnetic field.

Good call on the moon being tidally-locked to its primary. Jupiter’s and Saturn’s largest, closest moons are tidally-locked to their primaries (including Callisto). What this situation will do is make your moon’s day-night cycle quite a bit more interesting than just sunlight and darkness.

As the above mages shows, your moon will have a varying amounts of illumination - a time where only the star is visible (true day), a time where both star and primary is visible (brighter day), a time where the primary only is visible (false day), and a dark time where neither primary nor star is visible (true night). The moon will have a day length equal to the time it takes to orbit it’s primary.

Putting your moon at the same, safe distance as Callisto, it will orbit it’s primary in about 16.5 Earth days, so the moon’s ‘day’ will be just under 400 hours. If your moon orbits in the same plane that the primary’s orbit is in (and it probably does, cause that’s how most orbits work), you’ll have a short eclipse of the star by the primary every day for a couple of hours. Indeed, it’ll happen at local noon.

The tidal-locking of your moon probably wont have much of an effect on the planet’s environment. The side pointing towards the star will get really hot, seeing 200 hours of daylight, but it’ll cool off at night. The heat from the star will have much more impact than the heat form the primary. 

A good atmosphere and oceans (like Earth’s) will do a lot to spread the heat across the planet more evenly. It’ll probably have more extreme days and nights than Earth, but probably not enough to make living there too difficult.

Of course, the view from your moon would be spectacular. The primary will hang in the same spot in the sky looking about nine times the diameter of Earth’s full moon. It’ll be dozens of times brighter than the full moon, as well.

tl;dr:  Your setup is quite plausible and believable, and you’ve got the basics pretty good.. There is nothing known that would make such a setup implausible.

Hey, if it’s good enough for the Rebels…

So burning stars,
are all we are,
Ignited from within.
It’s your heart and soul, It’s your flesh and bones, don’t you let it go.

He is handsome alien cat and I love him.

Your fave is problematic: ESA
  • ESA (European space agency… or if you’re like, fancy, in French, fancy in French, French fanciness, Agence spatiale européenne) is an organization in which multiple countries are engaged in, dedicated to exploring space
  • these hennies do things like: human space flight, launching and operation unmanned missions, Earth observation, science and telecommunication and like, other stuff, ya kno
  • unlike NASA, ESA has 22 member countries, talk about collaboration yo
    • there’s even a treaty among the countries: ESA’s purpose shall be to provide for, and to promote, for exclusively peaceful purposes, cooperation among European States in space research and technology and their space applications, with a view to their being used for scientific purposes and for operational space applications systems
    • I may or may not be tearing up a little
  • because they’re like, so nice, they let Canada play with them too, so Canada (CSA) is an associated member of the ESA
  • ESA has a couple of dope-ass launch vehicles
    • Ariane 5: (yes, that’s the most German name ever) this gurl has been in use for 20 years! she’s been super successful, after an initial failed launch, she’s been transporting satellites into space for 71 successful starts in a row!
    • Soyuz: now, I kno, when you hear Soyuz, you think Russia, but hear me out: Roscosmos and ESA have an agreement in which Russia builds parts for the Soyuz launch vehicle and it gets assembled in French Guiana. Russia gets access to a good launch site for their launches, and ESA gets access to the very safe Soyuz launcher in exchange. [insert handshaking stock photo meme here]
  • Notable ESA missions that will blast your balls off:
    • Planck spacecraft: a cosmology mission that mapped the cosmic microwave background and essentially delivered amazing evidence for the age of the universe and cosmic inflation
    • Rosetta: ESA successfully landed on a COMET for the first time ever, telling us about the composition of comets. the spacecraft traveled 9 years to get there and yet they managed to land and signals. fuckin amazing
    • Huygens: ESA successfully landed a probe on Saturns moon, Titan.  This was the first and only landing ever accomplished in the outer Solar System! 
  • summary: neutral good organization, doesn’t know how to celebrate really but that’s how Europeans are, 12/10, would launch my satellite with them