Saturn’s moon Enceladus, new study


This video says about itself:

Warm Water Spots Found On Saturn’s Icy Moon Enceladus

12 March 2015

Astronomers have detected the first active hydrothermal vents outside of Earth’s seafloor on Saturn’s icy moon Enceladus, indicating conditions that could be hospitable to the initial development of life.

New research suggests the existence of warm spots on the ocean floor of Saturn’s icy moon Enceladus.

They could be the first active hydrothermal vents to be detected outside of Earth’s seafloor, and their conditions may even be similarly hospitable to the initial development of life.

Two studies, one led by the University of Colorado, Boulder and the other by the Southwest Research Institute in Texas, support the possible existence of this hydrothermal activity.

In 2005, the Cassini orbiter captured images of geysers shooting out of the moon’s surface, which led to the discovery of an underground sea believed to be approximately 6 miles deep and under about 25 miles of icy crust.

Scientists discovered particles from the geysers in one of Saturn’s rings and using an instrument onboard Cassini were able to analyze the tiny, uniform dust particles. They found they were rich in silica which is common on Earth but different from the usual ice crystals found in Saturn’s E-ring.

Because silica has such well-known properties, the only way they could create similar particles in the lab was using slightly alkaline, low-in-salinity water at temperatures of at least 194 degrees Fahrenheit.

Despite the ultra-cold environment, the moon’s high core temperature is thought to come from an effect called tidal heating where Saturn’s gravitational pull on the moon generates heat.

From the International Business Times:

On Saturn’s Moon Enceladus, Water Vapor Erupts In Giant Curtains: Study

By Avaneesh Pandey

May 08 2015 8:35 AM EDT

In 2005, NASA’s Cassini-Huygens spacecraft found evidence of an icy spray issuing from the southern polar region of Saturn’s sixth-largest moon, Enceladus. Now, just two months after scientists confirmed the presence of hydrothermal activity on the moon, researchers have claimed that the eruption of water vapor on its surface might be in the form of broad, curtain-like sheets, rather than discrete jets.

“We think most of the observed activity represents curtain eruptions from the ‘tiger stripe’ fractures, rather than intermittent geysers along them,” Joseph Spitale, a Cassini mission participating scientist and senior scientist at the Planetary Science Institute in Tucson, Arizona, said, in a statement, referring to prominent wavy fractures along the moon’s surface. “Some prominent jets likely are what they appear to be, but most of the activity seen in the images can be explained without discrete jets.”

According to a study published Thursday in the journal Nature, these “phantom jets” seen in simulated images produced by scientists line up perfectly with some of the features seen in real Cassini images. This means that the discrete geysers that scientists have observed on Enceladus are, in fact, an optical illusion created in places where these curtains fold against one another. This illusion is also responsible for creating regions of phantom brightness when viewers are looking through the folds of watery curtains.

“The viewing direction plays an important role in where the phantom jets appear,” Spitale said, in the statement. “If you rotate your perspective around Enceladus’ South Pole, such jets would seem to appear and disappear.”

On Earth, these curtain eruptions occur in regions of volcanic activity such as Hawaii, Iceland and the Galapagos Islands. However, unlike Enceladus’ watery curtains, these are curtains of fire.

Enceladus is believed to be covered with a layer of ice about 19 miles to 25 miles thick. Evidence strongly suggests that the moon harbors a six-mile-deep ocean, with temperatures reaching up to 194 degrees Fahrenheit below its thick, icy surface, making it a prime location to look for extraterrestrial life.

Planet Mercury craters named after Diego Rivera, Umm Kulthum, other artists


This video from the USA says about itself:

27 April 2015

The robotic spacecraft MESSENGER has run out of fuel. With no way to make major adjustments to its orbit around the planet Mercury, the probe will smash into the surface at more than 8,750 miles per hour (3.91 kilometers per second). The impact will add a new crater to the planet’s scarred face that engineers estimate will be as wide as 52 feet (16 meters).

From NASA in the USA:

April 29, 2015

Mercury Crater-Naming Contest Winners Announced

The MESSENGER Education and Public Outreach (EPO) Team, coordinated through the Carnegie Institution for Science, announces the winning names from its competition to name five impact craters on Mercury. The contest submissions had to be submitted by January 15, 2015, and the International Astronomical Union (IAU) — the governing body of planetary and satellite nomenclature since 1919 — made the selections from a semi-final submission of 17 artists’ names. The newly selected crater names are Carolan, Enheduanna, Karsh, Kulthum, and Rivera.

Under IAU rules, all new craters on Mercury must be named after an artist, composer, or writer who was famous for more than 50 years and has been dead for more than three years.

Turlough O’Carolan (Carolan), was an Irish composer during the late 1600s and early 1700s.

This music video features Turlough O’Carolan’s composition Planxty Irwin.

Enheduanna, an Akkadian princess who lived in the Sumerian city of Ur in ancient Mesopotamia (today’s Iraq and Kuwait), and is regarded by many scholars as possibly the earliest known author and poet.

This video is about Enheduanna.

Yousuf Karsh, was an Armenian/Canadian and one of the greatest portrait photographers of the twentieth century.

This video is called Profile of Photographer Yousuf Karsh.

Umm Kulthum, was an Egyptian singer, songwriter, and film actress of the 1920s to the 1970s.

This music video is called Umm Kulthum ( أم كلثوم ) live; “Enta Omri” (English subtitles). At the Olympia Théâtre in Paris, November 1967.

Diego Rivera, was a prominent Mexican painter and muralist from the 1920s to the 1950s.

This video is called Tribute to Diego Rivera.

NASA’s MESSENGER spacecraft has been in orbit about Mercury since March 2011 and is due to finally impact the planet tomorrow. The MESSENGER spacecraft has far surpassed expectations in the duration of the mission and in the quantity and quality of data returned. The original goal of the craft was to take 2,500 images of the planet, but is has returned more than 250,000. The EPO team organized the crater-naming competition to celebrate the mission’s achievements.

The winners come from many different countries. Carolan was suggested by Fergal Donnelly (Belgium), Joseph Brusseau (USA), and Reane Morrison (USA). Enheduanna was submitted by Gagan Toor (India). Karsh was submitted by Elizabeth Freeman Rosenzweig (USA). Kulthum was suggested by Malouk Ba-Isa (Saudi Arabia), Riana Rakotoarimanan (Switzerland), Yehya Hassouna (USA), David Suttles (USA), Thorayya Said Giovanelli (USA), and Matt Giovanelli (USA). Rivera was suggested by Ricardo Martinez (Mexico), Rebecca Hare (USA), Arturo Gutierrez (Mexico), and Jose Martinez (USA).

Julie Edmonds, the EPO team leader at the Carnegie Institution for Science, remarked, “The IAU working group that chose the names was very happy with the submissions. In all we had 3,600 contest entries, a resounding success for the excitement that the MESSENGER mission to Mercury has generated.”

Final Maneuver Extends MESSENGER Operations by One More Orbit

MESSENGER mission controllers at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., conducted a maneuver on April 28 designed to raise the spacecraft’s minimum altitude sufficiently to ensure impact onto Mercury during the desired orbit when full coverage by NASA’s Deep Space Network (DSN) scheduled.

The previous maneuver, completed on April 24, raised MESSENGER’s minimum altitude from 8.3 kilometers (5.2 miles) to 18.2 kilometers (11.3 miles) above the planet’s surface. Because of progressive changes to the orbit over time, however, the spacecraft’s minimum altitude continued to decrease.

At the time of this most recent maneuver, MESSENGER was in an orbit with a closest approach of 5.3 kilometers (3.3 miles) above the surface of Mercury. With a velocity change of 0.45 meters per second (1 mile per hour), the spacecraft’s four largest monopropellant thrusters released gaseous helium pressurant to nudge the spacecraft to an orbit with a closest approach altitude of 6.3 kilometers (3.9 miles).

This maneuver also increased the spacecraft’s speed relative to Mercury near the maximum distance from Mercury, adding about 3.5 seconds to the spacecraft’s eight-hour, 21.2-minute orbit period. The final maneuver in the MESSENGER low-altitude hover campaign, this was the mission’s fourth course-correction maneuver to use the helium gas pressurant as a propellant to change the spacecraft’s orbit. This view shows MESSENGER’s orientation at the start of the maneuver.

MESSENGER was 155.2 million kilometers (96.5 million miles) from Earth when the 3.02-minute maneuver began at about 5:20 p.m. EDT. Mission controllers at APL verified the start of the maneuver 8.6 minutes later, after the first signals indicating spacecraft thruster activity reached NASA’s DSN tracking station in Goldstone, California.

MESSENGER (MErcury Surface, Space ENvironment, GEochemistry, and Ranging) is a NASA-sponsored scientific investigation of the planet Mercury and the first space mission designed to orbit the planet closest to the Sun. The MESSENGER spacecraft was launched on August 3, 2004, and entered orbit about Mercury on March 18, 2011, to begin a yearlong study of its target planet. MESSENGER’s first extended mission began on March 18, 2012, and ended one year later. MESSENGER is now in a second extended mission, which is scheduled to operate through April 2015.

Dinosaurs, humans, sun and earth, medieval religious dogmas in Spain


This video says about itself:

Dinosaurs, and Creationism Debunked

1 March 2015

To believe that non-avian dinosaurs exist today or have ever existed with mankind is to show the highest level of ignorance in history, archaeology, and paleontology. This is my debunking of a creationist video that says dinosaurs once existed with man and that there is evidence for this in history.

From daily The Independent in Britain today:

One in three Spaniards thinks humans lived at the same time as dinosaurs

Today in worrying news, 30 per cent of people in Spain think humans lived at the same time as dinosaurs.

A government-backed study also showed 25 per cent of respondents think the Sun orbits the Earth.

One positive to take from the Social Perception of Science study, from Spain’s Foundation for Science and Technology, is that at least scientific knowledge is improving in the country – in 2006 the proportion of people believing the previous two incorrect assertions was 50 per cent for dinosaurs and 40 per cent for the Sun.

Overall, nine years ago people answered 58 per cent of questions correctly, while now the ratio is 70 per cent.

This video says about itself:

Testing Geocentrism

15 November 2012

… a series on geocentrism, these videos take a wry look at the subject and how it stacks up against basic observations. This part [1] looks at whether the geocentrist explanation of the seasons holds any merit, why Polaris doesn’t move and how basic observations of the inner and outer planets hold up to the ideas of the geocentrist. A simple introduction is given to relevant concepts, providing topic pointers for the viewer who wants to find out more for themselves.

Subtitles: English
Guidance: Contains some mild language within a comedy context.

* I noticed after completing this video that the introduction should have said “Over two thousand years after Aristarchus” not “Nearly one thousand”.

Lyrid meteor shower tomorrow


This video from the USA says about itself:

How to View a Meteor Shower | California Academy of Sciences

30 December 2014

Here are some fun tips for observing the upcoming meteor shower, brought to you by the California Academy of Sciences.

The California Academy of Sciences writes about this today:

On any given night, meteors can be seen as tiny particles of space dust burn up in Earth’s atmosphere. Don’t miss the next major meteor shower, the Lyrids, peaking tomorrow, April 22. Watch this helpful video to brush up on your meteor-spotting skills!

Astronomy Day, 25 April


This video from the USA is called 365 Days of Astronomy.

From the California Academy of Sciences in the USA:

We’re teaming up with NASA to celebrate Astronomy Day this Saturday, April 25! Touch a meteorite, learn about telescopes, observe the 3D nature of constellations, and more.

Explore Your Universe at the Academy

April 25 is Astronomy Day—an international celebration of space. This year, the Academy will explore the past, present, and future of space observation. Discover the wonders of the cosmos with special programing all day long.

Event highlights:

• Join us for PLUTO-PALOOZA, an epic celebration of space exploration with partners from NASA and SETI.

• Celebrate the 25th anniversary of the Hubble Space Telescope with Hubble-themed Hohfeld Hall shows.

• Test your space smarts with a Cosmic Quiz Show.

• Catch our newest award-winning show, Habitat Earth, in Morrison Planetarium, our 75-foot digital immersive dome and gain new perspective about our own planet.

Click for More Astronomy Day Events here.

Glaciers on Mars, covered by dust, discovered


This 7 April 2015 video is called Glacial Belts of Water Ice Found On Mars.

From Astronomy Now:

Mars has belts of glaciers composed of water ice

8 April 2015

Mars has distinct polar ice caps, but Mars also has belts of glaciers at its central latitudes in both the southern and northern hemispheres. A thick layer of dust covers the glaciers, so they appear as surface of the ground, but radar measurements show that underneath the dust there are glaciers composed of frozen water. New studies have now calculated the size of the glaciers and thus the amount of water in the glaciers. It is the equivalent of all of Mars being covered by more than one metre of ice. The results are published in the scientific journal Geophysical Research Letters.

Several satellites orbit Mars and on satellite images, researchers have been able to observe the shape of glaciers just below the surface. For a long time scientists did not know if the ice was made of frozen water (H2O) or of carbon dioxide (CO2) or whether it was mud. Using radar measurements from the NASA satellite, Mars Reconnaissance Orbiter, researchers have been able to determine that it is water ice. But how thick is the ice and do the glaciers resemble glaciers on Earth? A group of researchers at the Niels Bohr Institute have now calculated this using radar observations combined with ice flow modelling.

Data Combined with Modelling

“We have looked at radar measurements spanning ten years back in time to see how thick the ice is and how it behaves. A glacier is after all a big chunk of ice and it flows and gets a form that tells us something about how soft it is. We then compared this with how glaciers on Earth behave and from that we have been able to make models for the ice flow,” explains Nanna Bjørnholt Karlsson, a postdoc at the Center for Ice and Climate at the Niels Bohr Institute at the University of Copenhagen.

Nanna Bjørnholt Karlsson explains that earlier studies have identified thousands of glacier-like formations on the planet. The glaciers are located in belts around Mars between the latitudes 30° and 50° — equivalent to just south of Denmark’s location on Earth. The glaciers are found on both the northern and southern hemispheres.

From some locations on Mars they have good detailed high-resolution data, while they only have more sparse data from other areas. But by supplementing the sparse data with information about the flow and form of the glaciers from the very well studied areas, they have been able to calculate how thick and voluminous the ice is across the glacier belts.

Could Cover the Entire Planet

“We have calculated that the ice in the glaciers is equivalent to over 150 billion cubic metres of ice — that much ice could cover the entire surface of Mars with 1.1 metres of ice. The ice at the mid-latitudes is therefore an important part of Mars’ water reservoir,” explains Nanna Bjørnholt Karlsson.

That the ice has not evaporated out into space could actually mean that the thick layer of dust is protecting the ice. The atmospheric pressure on Mars is so low that water ice simply evaporates and becomes water vapour. But the glaciers are well protected under the thick layer of dust.

Nasa’s Curiosity rover finds water below surface of Mars. New measurements from the Gale crater contradict theories that the planet is too cold for liquid water to exist, but Mars still considered hostile to life: here.

Will extra-terrestrial life be discovered soon?


This video is from the film War Of The Worlds (2005)– The First Tripod.

The film is about an invasion of the USA by dangerous Martians. In the original book by H.G. Wells, the dangerous Martians invaded England.

Very probably, extra-terrestrial life, if any will be discovered soon, will be very unlike that.

From daily The Independent in Britain:

We will have definitive evidence of alien life in 20 years, Nasa chief scientist believes

Strong indications of life beyond Earth could be found within a decade

Christopher Hooton

Wednesday 08 April 2015

The discovery of extra-terrestrial life, probably the most exciting event in human history, may well take place within most of our lifetimes, a high-ranking Nasa scientist has predicted.

“I think we’re going to have strong indications of life beyond Earth within a decade, and I think we’re going to have definitive evidence within 20 to 30 years,” Nasa chief scientist Ellen Stofan said on Tuesday, during a panel discussion focusing on the space agency’s search for habitable environments outside of Earth.

“We know where to look. We know how to look,” Stofan added, “In most cases we have the technology, and we’re on a path to implementing it. And so I think we’re definitely on the road.”

Nasa believes such discoveries could happen so soon as they will not take place in deep space but in our own solar system and others in the Milky Way.

Sharing Stofan’s optimism, associate administrator for Nasa’s Science Mission Directorate John Grunsfeld said: “I think we’re one generation away in our solar system, whether it’s on an icy moon or on Mars, and one generation [away] on a planet around a nearby star.”

If life, in whatever form it takes, is found in orbit of the Sun, it could well be on Jupiter’s moons Europa and Ganymede or Saturn‘s satellite Enceladus, which hold seas beneath their icy surfaces.

The Milky Way is “a soggy place,” Paul Hertz, director of Nasa’s Astrophysics Division, explained.

“We can see water in the interstellar clouds from which planetary systems and stellar systems form.

“We can see water in the disks of debris that are going to become planetary systems around other stars, and we can even see comets being dissipated in other solar systems as [their] star evaporates them.”

These estimates don’t even take into account the fact that alien life may be able to prosper in conditions different to those required by humans, e.g without need for water.

NASA SUPER-TEAM TO LOOK FOR HABITABLE PLANETS, EXTRATERRESTRIAL LIFE The news comes a week after NASA’s chief said we’d have strong evidence of extraterrestrial life in a decade. [Ed Mazza, HuffPost]