Daily Space 8/06/2019

Aug 6, 2019 | Uncategorized

The #DailySpace brings you the universe at 10am PST / 1pm EST / 5pm GMT on twitch.tv/CosmoQuestX. Today’s #spacenews includes the following stories:

Back on April 11, Israel’s SpaceIL tried to land the Beresheet lander on the moon. They failed, but while the spacecraft was a total lose, there may still have been survivors. It turns out, the spacecraft was packing a population of tardigrades – extremely small extremophiles that generally refuse to die.

Nicknamed water bears, these roughly 0.4mm many legged critters can live for years without food or water. This means, there may now be a population of 1000s of water bears living – for very small values of living – on the moon.

Now, I don’t want you to get me wrong – these tardigrades aren’t off partying in the lunar dust; they aren’t setting up colonies – hack they probably aren’t even reproducing! They are at this moment shut down and in hibernation… on the moon.

What do we do with this information? No idea. It does tell me, however, that we need to not just sterilize the outsides of the spacecrafts we send to Mars, we also need to sterilize the insides, because accidents happen, and you never know when you just might be seeding life on another world by crashing into it.

Today’s next story is one of looking for dead things instead of living things. As we talked about last week, when stars like our Sun will eventually stop burning hydrogen in their cores and when this happens they will undergo somewhat rapid expansion. During this giant phase, it will roast off the outer layers of its systems stars, and maybe even consume a few of them. This will continue throughout its giant phase, and it will even spray its atmosphere all over the place as they transition from from star to white dwarf and planetary nebula.

Now, scientists from Penn State, have modeled the life and near death of these planets to try and understand if those planets can be detected.

The answer is yes, these reminders of worlds can be seen for a billion observable years after their parent star has died. These little hot embers will be detectable in radio. This means, we may be able to detect dead planets around dead stars, which is morbid, but could allow us to work backwards to figure out when stars first started having planets.

White dwarfs play a lot of roles in astronomy, and one of the more interesting roles the play is that of essentially a stick of dynamite. When these stars acquire enough mass, either by stealing it from another star, or by having it blown onto them by a nearby star. These, always the same mass when they explode stars are used as standard candles to measure the size of the universe.

The thing is, there has always been this question: are they actually always the same mass when they explode? The leading theory has been “Yes – mostly… we think.” On a fairly regular basis, however, new papers come out describing why this may not be true, and why our standard candles may not be so standard. In a paper coming out in the Astrophysical Journal today, a team led by CalTech’s Evan Kirby describes a whole variety, of ways white dwarfs might not so randomly explode at a variety of different sizes depending on their composition. This work is a tangle of observations and theoretical models that when put together are fairly conniving… but that doesn’t mean it’s true… yet. Science is a process and one of the things that makes this particular kind of problem hard to sort is the type 1a supernova models make sense and give us low noise graphs that make sense. If metallicity is the dominant factor in deciding when white dwarfs explode, we might expect more noise in the data… maybe. Maybe.

This is where we need that one clear thinker to come along and take a stab at reviewing all we’ve seen and all we’ve thought and define what limits reality imposes. For now, we’re just going to have to settle for maybe.

Join us tomorrow for more Daily Space news – and keep mapping Bennu!

0 Comments

Got Podcast?

365 Days of Astronomy LogoA community podcast.

URL * RSS * iTunes

Astronomy Cast LogoTake a facts-based journey.

URL * RSS * iTunes * YouTube

Visión Cósmica LogoVisión Cósmica

URL * RSS

Escape Velocity Space News LogoEscape Velocity Space News
New website coming soon!
YouTube

Become a Patron!
CosmoQuest and all its programs exist thanks the generous donations of people like you! Become a patron & help plan for the future while getting exclusive content.