Space, Planets and eclipses

[JustKelli]

This is the ISS and her 6 docking stations

[truc1979]

A study from a polish team reveals that the milky was is actually not flat. The disc is a little twisted. (second picture below is an animated gif)

[JustKelli]

^^^^^ Very cool thanks for adding your interesting thoughts and images.



This Impact Crater Was Likely Ground Zero for an Ancient Mega-Tsunami on Mars

By*Mike Wall*a day ago*Science & Astronomy*

Lomonosov Crater may be ground zero.*****

Mars' 75-mile-wide (120 kilometers) Lomonosov Crater, as seen by NASA's Mars Global Surveyor orbiter.

[Pictured above]

Ground zero for the impact that caused a*Mars*mega-tsunami more than 3 billion years ago may have been found.

The meteor that spawned that ancient flood probably blasted out Lomonosov Crater, a 75-mile-wide (120 kilometers) hole in the ground in the icy plains of the Martian Arctic, a new study reports.*

Lomonosov's large size suggests that the impactor itself was big — similar in scale to the 6-mile-wide (10 km) asteroid that hit Mexico's Yucatan Peninsula 66 million years ago, sparking a mass extinction that killed off 75% of Earth's species,*including the dinosaurs.

Related:*The Search for Water on Mars in Pictures

Such big space rocks don't hit the Red Planet (or Earth) very often. So, the new study provides some important clues about Mars' ancient northern ocean, and the planet's*past potential to host life*as we know it, team members said.

"The implication is that the ocean would have retained a liquid component for a very long time," study co-author Alexis Rodriguez, a senior scientist at the Planetary Science Institute in Tucson, Arizona, told Space.com. He offered 4 million to 5 million years as a representative figure, but stressed that the number is just an estimate.

A cold and mysterious ocean

Mars'*big, salty northern ocean*likely formed about 3.4 billion years ago. The ocean's existence is widely accepted by Mars researchers, Rodriguez said, but there is considerable debate about its nature.*

For example, some scientists believe the ocean was relatively long-lived, if quite cold. But others don't think the ancient Martian climate could have supported stable bodies of surface water for long, and therefore argue that the ocean froze over very quickly — perhaps in a few thousand years or less.

The*new study, which was published in late June in the Journal of Geophysical Research: Planets, bolsters the former viewpoint.

Rodriguez and his colleagues, led by François Costard of the French National Center for Scientific Research, built upon several years of previous research into the ocean and its imprints on the landscape of ancient Mars.

For example, Rodriguez led a 2016 study that identified huge lobes in the northern plains — features that strongly resemble marks left by tsunamis here on Earth. The team determined that the lobes were carved out by*two different mega-tsunamis, which flooded the region more than 3 billion years ago.

Mars does not have significant plate-tectonic activity, so the big waves were probably unleashed by impacts. So, Costard, Rodriguez and their colleagues hunted for craters left behind by the cosmic culprits, narrowing the search over the next few years.

That search may now be over, at least for one of the two impactors. Multiple lines of evidence point to Lomonosov, the scientists report in the new study. For example, Lomonosov is in the right place, it's the right age (as determined by crater counts), and it looks a lot like marine craters here on Earth.

Lomonosov fits the bill in other ways as well. For instance, the crater is about as deep as scientists think the shallow northern ocean was at the time of impact. And part of Lomonosov's rim is missing, which is consistent with a mega-tsunami; the displaced water may have knocked this big chunk free as it raged.

While this evidence is suggestive, however, it does not yet rise to the level of a smoking gun, Rodriguez said.

"This crater is a candidate," he said. "I would not go so far as to say this is definitely the crater that produced the tsunami."

That tsunami, by the way, is probably the first of the two big floods that Rodriguez and his colleagues identified back in 2016. That earlier mega-tsunami featured both runoff and backwash flows, the latter of which are caused by water returning to the sea. Lomonosov seems to have been carved by both types of flows.

The second mega-tsunami caused runoff but not backwash, suggesting that Mars, and the ocean, may have been colder at the time. It's possible the northern ocean had a significant amount of ice cover when this other impactor came crashing down, he added.*

Boosting the case for Mars life?

Lomonosov is interesting enough on solely geological grounds.

"This is possibly the first time that a potential marine crater associated with a tsunami has been investigated outside Earth," Rodriguez said.

And then there are the astrobiological implications. As noted above, Lomonosov's size suggests the northern ocean —*a potentially habitable environment — persisted for a relatively long time. It's statistically unlikely, after all, that the Lomonosov impact occurred right after this liquid ocean formed.

And even if the ocean were largely frozen at the time, the impact would have created an environment favorable to life as we know it: The tremendous energy unleashed would have melted lots of ice and created a*hydrothermal system*at Lomonosov, Rodriguez said.

The crater is therefore a tantalizing target for future life-hunting missions. Robotic explorers probably aren't up to the task, however, because the Lomonosov area is covered by an ice layer about 33 feet (10 meters) thick, Rodriguez said.*

But human explorers could probably drill down through the ice and access sediments on the crater floor. And these pioneers could use the abundant water ice for life support, providing an exploration twofer.

"That would be very interesting," Rodriguez said.

[JustKelli]

Does anyone remember Darpa from 2011. It was a supersonic craft that flew Mach 20 for 3 minutes before face planting in the Pacific?

Anyway ...



Different DARPA Hypersonic Vehicles 'On Track' to Fly in 2019

Concept art: Raytheon

Two hypersonic vehicle prototypes developed by the Defense Advanced Research Projects Agency and the Air Force are due to fly by the end of the year, the agency’s director said May 1.

One vehicle is part of the hypersonic air-breathing weapon concept, or HAWC, program. The other is the tactical boost glide, or TBG, effort, said Steven Walker.

“We're on track for both to have flights … before the calendar year ends,” he told reporters during a breakfast meeting in Washington, D.C. However, that might be questionable because once "you actually get into the building of these things and qualifying the hardware, … things tend to slip.”

Walker said there is a chance the vehicles could fly in early 2020, but was hopeful that that would not be the case. DARPA has been working on both efforts alongside the Air Force since 2012, he noted.*

“These [efforts] were focused on more tactical theater-level operations,” he said.*

TBG is meant to develop an advanced boost-glide system that can be launched from a rocket, he said. The HAWC concept takes advantage of work DARPA has previously done in scramjet technology to create a system that can be self-powered after being launched from an aircraft such as a B-52. According to the agency, HAWC focuses on three technology challenge areas including air-vehicle feasibility, effectiveness and affordability.

“Two very different concepts but when you're talking hypersonics it's good to have what I consider intended redundancy because it's a hard technology making materials and propulsion systems that last in 3,000-degree Fahrenheit temperatures,” he said.

Walker said he is still unsure of which vehicle will fly first. “It's really a race between HAWC and TBG to see which one goes first,” he said.*

However, a number of hurdles could potentially delay the flights, he noted. Both systems are currently in the early stages of their assembly, integration and test phases.

“You have to qualify all the hardware components [and] sometimes you run into issues with qual tests,” he said. “You got to re-qualify things, put that all together and [then] you test the whole system and you hope it all works and has been done correctly. … [There are] all sorts of things once you get into testing real hardware that you have to face down every day and beat back.”

Hypersonic vehicles — which can fly at speeds in excess of Mach 5 — have become increasingly important technology areas to the Defense Department writ large.*

“It’s an area that I believe the U.S. really needs to make progress in and be a leader in,” Walker said. “From a technology standpoint, … we have led the way in hypersonics. I think some of our peer competitors though have taken that technology and turned it into capability faster than we have.”

The advantage of hypersonic vehicles is not just time of flight, but also the range that would be achieved by the high-speed vehicle just because of physics, he said.*

“You also get a lot of potential maneuverability that we don't have today,” he said. It’s “a combination of all those factors [that] make it an attractive technology, which is why our adversaries are working on them.”

Walker noted that DARPA is also engaged with the Army and Navy on hypersonic-related activities.

It is currently working with the Army on a program that takes advantage of technology leveraged from the tactical boost glide effort, he said. The system — known as Operational Fires, or OpFires — is a 50/50 cost share and will give the service a ground-launched capability to penetrate modern enemy air defenses.

“It's a brand-new booster,” he said. “This new booster would allow a lot more controllability, mobility for the Army and an ability to really use the system in the most effective way versus any other existing booster that's out there.”

DAPRA is also engaged with the Navy on a study about whether or not the agency’s HAWC vehicle would be a good fit for the sea service, Walker said.

However, “that study I believe is still underway,” he said. “They have not committed to moving forward with that system.”

[JustKelli]

Have you ever wondered how big asteroids really are? Here is Rosetta compared to Los Angeles ... that's gonna leave a mark!!!

That puppy is flying through space at around 100,000 mph just looking for something to hit ... newsflash, it ain't stopping when finds something.

[LongTimeLu]

That's a truly impressive picture and makes you realise how small and delicate we are when that thing is 'only' 2.5 miles across, middle-ish for asteroids.

I am amazed to find out that if you could gather all the asteroids together they would only make about a quarter of the moon
While space is incredibly big, things in it are incredibly small and even our local space is mostly empty.


Sorry to be a pedant but while I was searching for actual data on the size it seems the picture is actually of comet 67P/Churyumov–Gerasimenko, Rosetta is the craft that landed there.

[Uranium236]

Originally Posted by LongTimeLu

I am amazed to find out that if you could gather all the asteroids together they would only make about a quarter of the moon

I dunno about that. Seems like an extremely conservative estimate.

You Tube

You Tube

[JustKelli]

Meet the IXS concept warp drive vehicle that is on the drawing board at NASA. It is space travel meets Star Trek stuff with the idea that faster than the speed of light can get explorers to places like Alpha Centauri in 2 weeks instead of the current 4.3 light years ... it was originally proposed in 2012

[vimla]

Originally Posted by JustKelli

Meet the IXS concept warp drive vehicle that is on the drawing board at NASA. It is space travel meets Star Trek stuff with the idea that faster than the speed of light can get explorers to places like Alpha Centauri in 2 weeks instead of the current 4.3 light years ... it was originally proposed in 2012

I'll believe it when I see the spaceship in action, as Einstein calculated nothing cab travel faster then light.

And when you come up in those speeds you really bend space and time, as those in the spaceship will time go slower opposed those outside.

So in theory you could travel forward in time by riding a ship that can travel up to lightspeed and come to earth again, you could be younger then your grand grand children

[LongTimeLu]

Originally Posted by Uranium236

I dunno about that. Seems like an extremely conservative estimate.

You Tube

Yup! like I said - it amazed me. Here's NASA

Originally Posted by http://solarsystem.nasa.gov/asteroids-comets-and-meteors/asteroids/in-depth/

The total mass of all the asteroids combined is less than that of Earth's Moon.

And this from Western Washington University

Originally Posted by http://wwu.edu/planetarium/a101/a101_asteroids.shtml

Here is a table that shows the number of asteroids in groups according to size, and the total volume of material in each group.

Add up the values in the last column to estimate the total volume of material that is contained within the asteroid belt: 4.87 x 10^8 km3 The volume of the Earth is roughly 1.0 x 10^12 km3. What approximate percentage of the Earth’s volume does the sum of all the asteroid volume represent: 0.0487%, an extremely small fraction of the volume of the Earth!

Wiki has a complex chart (LTL://en.wikipedia.org/wiki/Asteroid#Size_distribution)
and data (LTL://en.wikipedia.org/wiki/List_of_Solar_System_objects_by_size)
that is too long to post, but as you can see from the above data most of the mass of the asteroids is contained in a some quite large objects and the rest are tiny in comparison.

Here's some approximations:
The moon is 3600km across so it's volume is 22x10^9 km3
Ceres is 950km across so it's volume is 0.45x10^9 km3,
i.e 2% the volume of the moon! So when I suggested a quarter - I was being generous!

Thanks for making me look again at the figures - it truly screws me up that space may be vast but it is mostly empty.
Which makes that video you posted - not exactly a lie - but he does say at 2m40 that one pixel is 500km across at high resolution. He is exagerating the size of the asteroids for clarity of visuals.