Astronomy

[Dreamwoven]

http://earthsky.org/space/1st-direct...izon-telescope

Editor’s Note: We originally posted this story in late 2017, but it has proven so popular that we’re bringing it back to the forefront now. This story is definitely one to watch in 2018.

In late 2017, scientists with the Event Horizon Telescope – an international collaboration that’s created a virtual Earth-sized telescope, with the goal of capturing the first direct image of a black hole – reported on a the long-awaited shipment of hard disk drives from the South Pole. They said they were busily analyzing the data on these drives, which is expected to be a key component in giving us the first-ever direct image of a black hole sometime in 2018. An article at news.com.au reported:

The data is in. The numbers are being crunched.

The Vox.com video above explains that nearly all images we see of black holes are artist’s illustrations. The ones that aren’t illustrations show, at best, the effects of black holes on the space around them – for example, stars in tightly bound orbits, gas heated to high temperatures, or relativistic jets.

So what are scientists with the Event Horizon Telescope expecting to see?

[Danik 2016]

http://earthsky.org/space/measuring-...eveals-mystery

By Donna Weaver and Ray Villard/Johns Hopkins

Here’s the good news: Astronomers have made the most precise measurement to date of the rate at which the universe is expanding since the Big Bang.

Here’s the possibly unsettling news: The new numbers remain at odds with independent measurements of the early universe’s expansion, which could mean that there is something unknown about the makeup of the universe.

Is something unpredicted going on in the depths of space?

Adam Riess is a Nobel Laureate and Bloomberg Distinguished Professor at Johns Hopkins University. He said:

The community is really grappling with understanding the meaning of this discrepancy.

Riess leads a team of researchers using the Hubble Space Telescope to measure the expansion rate of the universe. He shared a Nobel Prize in 2011 for the discovery of the accelerating universe.

The team, which includes researchers from Hopkins and the Space Telescope Science Institute, has used the Hubble Space Telescope over the past six years to refine the measurements of the distances to galaxies, using stars as milepost markers. Those measurements are used to calculate how fast the universe expands with time, a value known as the Hubble constant.
By Donna Weaver and Ray Villard/Johns Hopkins

Very interesting article, DW. But most of the recent publications show that the usual models for evaluating the universe have to be updated. As astronomical knowledge increases, new questions arise.

[Danik 2016]

http://earthsky.org/space/1st-direct...izon-telescope

Editor’s Note: We originally posted this story in late 2017, but it has proven so popular that we’re bringing it back to the forefront now. This story is definitely one to watch in 2018.

In late 2017, scientists with the Event Horizon Telescope – an international collaboration that’s created a virtual Earth-sized telescope, with the goal of capturing the first direct image of a black hole – reported on a the long-awaited shipment of hard disk drives from the South Pole. They said they were busily analyzing the data on these drives, which is expected to be a key component in giving us the first-ever direct image of a black hole sometime in 2018. An article at news.com.au reported:

The data is in. The numbers are being crunched.

The Vox.com video above explains that nearly all images we see of black holes are artist’s illustrations. The ones that aren’t illustrations show, at best, the effects of black holes on the space around them – for example, stars in tightly bound orbits, gas heated to high temperatures, or relativistic jets.

So what are scientists with the Event Horizon Telescope expecting to see?

That is a good question:
"Astronomers with the Event Horizon Telescope aren’t aiming to capture the black nothingness of a black hole itself (that’s not possible), but instead a black hole’s event horizon, the sphere-like point-of-no-return surrounding a black hole."

[Dreamwoven]

Good point, Danik!

[Danik 2016]

Thanks!

The Complete Transmission Spectrum of WASP-39b with a Precise Water Constraint
H. R. Wakeford
http://imgsrc.hubblesite.org/hvi/upl..._39b_paper.pdf

[Danik 2016]

https://www.ted.com/talks/stephen_ha...t_the_universe

[Dreamwoven]

http://earthsky.org/space/pluto-spac...9-ultima-thule

This is an update on the next New Horizons encounter. It is a long journey:

"Some 115,000 people from around the world recently suggested some 34,000 possible nicknames for the distant object 2014 MU69, the next target of the New Horizons spacecraft, whose historic sweep past Pluto took place in July 2015. The New Horizons mission team announced on March 13, 2018, it has selected the name Ultima Thule – pronounced ultima thoo-lee – for New Horizon’s next target, a Kuiper Belt object officially named 2014 MU69. New Horizons will sweep closest to Ultima Thule on January 1, 2019. The mission team describes the object as:

… the most primitive world ever observed by spacecraft, in the farthest planetary encounter in history.

In a statement, the team explained their reasons for their choice:

Thule was a mythical, far-northern island in medieval literature and cartography. Ultima Thule means “beyond Thule” – beyond the borders of the known world – symbolizing the exploration of the distant Kuiper Belt and Kuiper Belt objects that New Horizons is performing, something never before done.

[Dreamwoven]

I've never pronounced it as Thulee, odd.

[Dreamwoven]

https://www.space.com/39992-dwarf-pl...active-surface

Growing patches of ice and minerals associated with liquid water reveal that the dwarf planet Ceres is still evolving.

Researchers studying the warmer region of Ceres — the largest object in the asteroid belt between Mars and Jupiter — have noticed that a patch of ice has grown larger over time. In addition, a separate team found carbon-rich minerals on Ceres' surface that do not last long . Together, the new discoveries suggest that water still has a powerful presence on the tiny world.

Using NASA's Dawn spacecraft, the researchers studied the surface of the dwarf planet. The first team, led by Andrea Raponi, of the Italian National Institute for Astrophysics (INAF), found a growing patch of ice on Juling Crater, found in the midlatitudes. They suspect that water from the crater floor is condensing on the wall, causing a patch of ice to grow larger. [7 Strange Facts About Dwarf Planet Ceres]

[Danik 2016]

http://earthsky.org/space/pluto-spac...9-ultima-thule

This is an update on the next New Horizons encounter. It is a long journey:

"Some 115,000 people from around the world recently suggested some 34,000 possible nicknames for the distant object 2014 MU69, the next target of the New Horizons spacecraft, whose historic sweep past Pluto took place in July 2015. The New Horizons mission team announced on March 13, 2018, it has selected the name Ultima Thule – pronounced ultima thoo-lee – for New Horizon’s next target, a Kuiper Belt object officially named 2014 MU69. New Horizons will sweep closest to Ultima Thule on January 1, 2019. The mission team describes the object as:

… the most primitive world ever observed by spacecraft, in the farthest planetary encounter in history.

In a statement, the team explained their reasons for their choice:

Thule was a mythical, far-northern island in medieval literature and cartography. Ultima Thule means “beyond Thule” – beyond the borders of the known world – symbolizing the exploration of the distant Kuiper Belt and Kuiper Belt objects that New Horizons is performing, something never before done.

última= last.
I would have preferred Tiramisu!

[Danik 2016]

https://www.space.com/39992-dwarf-pl...active-surface

Growing patches of ice and minerals associated with liquid water reveal that the dwarf planet Ceres is still evolving.

Researchers studying the warmer region of Ceres — the largest object in the asteroid belt between Mars and Jupiter — have noticed that a patch of ice has grown larger over time. In addition, a separate team found carbon-rich minerals on Ceres' surface that do not last long . Together, the new discoveries suggest that water still has a powerful presence on the tiny world.

Using NASA's Dawn spacecraft, the researchers studied the surface of the dwarf planet. The first team, led by Andrea Raponi, of the Italian National Institute for Astrophysics (INAF), found a growing patch of ice on Juling Crater, found in the midlatitudes. They suspect that water from the crater floor is condensing on the wall, causing a patch of ice to grow larger. [7 Strange Facts About Dwarf Planet Ceres]

Looks like a kind of winter on Ceres.

[Dreamwoven]

I guess its climate is similar. Wintery and cold!

[Dreamwoven]

THE SOCIETY FOR POPULAR ASTRONOMY

Electronic News Bulletin No. 465 2018 March 18

"THE WORSENING COSMIC-RAY SITUATION
Spaceweather.com
New research conducted by the University of New Hampshire has revealed that
radiation from deep space is dangerous and intensifying faster than was
previously predicted. The story begins four years ago when scientists first
sounded the alarm about cosmic rays. Analyzing data from the Cosmic Ray
Telescope for the Effects of Radiation (CRaTER) instrument onboard NASA's
Lunar Reconnaissance Orbiter (LRO), they found that cosmic rays in the
Earth--Moon system were peaking at levels never before seen in the Space
Age. The worsening radiation environment, they pointed out, was a potential
peril to astronauts, curtailing how long they could safely travel through
space. A figure from their original 2014 paper shows the number of days a
30-year old male astronaut flying in a spaceship with 10 g/cm2 of aluminium
shielding (a wall thickness of nearly 4 cm) could go before reaching NASA-
mandated radiation limits. In the 1990s, the astronaut could spend 1000
days in interplanetary space, but in 2014 only 700 days. Galactic cosmic
rays come from outside the Solar System. They are a mixture of high-energy
photons and sub-atomic particles accelerated towards the Earth by supernova
explosions and other violent events in the cosmos. Our first line of
defence is the Sun. The Sun's magnetic field and the solar wind combine to
create a porous 'shield' that fends off cosmic rays attempting to enter the
Solar System. The shielding action of the Sun is strongest during Solar
Maximum and weakest during Solar Minimum. The problem is, as the authors
note in their new paper, the shield is weakening. Over the last decade, the
solar wind has exhibited low densities and magnetic field strengths,
representing anomalous states that have not been observed previously during
the Space Age. As a result of the remarkably weak solar activity, there
have also been the highest fluxes of cosmic rays. In 2014, the team used a
leading model of solar activity to predict how bad cosmic rays would become
during the next Solar Minimum, now expected in 2019-2020. Their previous
work suggested a ~20% increase of dose rates from one solar minimum to the
next. In fact, the actual dose rates observed by CRaTER in the last 4 years
exceed the predictions by ~10%, showing that the radiation environment is
worsening even more rapidly than was expected.

The data have come from CRaTER on the LRO spacecraft in orbit around the
Moon, which is point-blank exposed to any cosmic radiation that the Sun
allows to pass. Here on Earth, we have two additional lines of defence: the
magnetic field and the atmosphere of our planet. Both mitigate cosmic rays.
But even on Earth the increase is being felt. Scientists have been
launching space-weather balloons to the stratosphere almost weekly since
2015. Sensors onboard those balloons show a 13% increase in radiation
(X-rays and gamma-rays) penetrating our planet's atmosphere. X-rays and
gamma-rays detected by the balloons are 'secondary cosmic rays', produced
by the crash of primary cosmic rays into the upper atmosphere. They trace
radiation percolating down toward our planet's surface. The energy range of
the sensors, 10 keV to 20 MeV, is similar to that of medical X-ray machines
and airport security scanners. How does that affect us? Cosmic rays
penetrate commercial airlines, dosing passengers and flight crews so much
that pilots are classified by the International Commission on Radiological
Protection as occupational radiation workers. Some research shows that
cosmic rays can seed clouds and trigger lightning, potentially altering
weather and climate. Furthermore, there are studies linking cosmic rays
with cardiac arrhythmias in the general population. Cosmic rays can be
expected to intensify even more in the years ahead as the Sun enters what
may be the deepest Solar Minimum in more than a century."

[Danik 2016]

That seems a much more relevant study than all that wish fulfillment dreams about habitable planets and ETs. It might explain maybe why so much people are affected by cancer.

"How does that affect us? Cosmic rays
penetrate commercial airlines, dosing passengers and flight crews so much
that pilots are classified by the International Commission on Radiological
Protection as occupational radiation workers. Some research shows that
cosmic rays can seed clouds and trigger lightning, potentially altering
weather and climate. Furthermore, there are studies linking cosmic rays
with cardiac arrhythmias in the general population. Cosmic rays can be
expected to intensify even more in the years ahead as the Sun enters what
may be the deepest Solar Minimum in more than a century."

[Dreamwoven]

The link to cardiac arrhythmias is what I have had since I got an artificial mitral valve in my heart operation in 1999. I suffered a bit from this when I went out for a short walk in very cold weather a couple of weeks ago. There was a bitterly cold north wind at the time, during the deepest Solar Minimum in more than a century: https://en.wikipedia.org/wiki/Heart_arrhythmia. I am much more careful since then.