www.henley-times.org
www.henley-times.org

 

 

 

Comet 67P

 

 

 

 

Europe’s Rosetta mission ended its 12-year mission on Friday 30th September 2016 with a low-speed belly-flop on comet 67P Churyumov-Gerasimenko, concluding an interplanetary odyssey that gave humanity a first close-up introduction to a class of objects which has stimulated imaginations for millennia.

The crash landing was a dramatic punctuation to the Rosetta mission, intended to record observations and imagery closer to a comet than ever before.

The descent began at around 2050 GMT Thursday with a 208-second burn by Rosetta’s rocket thrusters, setting the probe on a course for a 20-kilometre descent toward a point on the dual-lobed comet’s smaller chunk.

Rosetta’s OSIRIS science camera took pictures throughout the descent, beaming the images across 720 million kilometers of desolate space back to Earth.

The last image from OSIRIS came from an altitude of about 20 meters, moments before Rosetta set down on the comet’s core at a projected speed of about 90 centimeters per second, an average walking pace.

Engineers received the last signal from Rosetta at 1119:19 GMT, when a graphical display flat-lined inside the European Space Operations Center in Darmstadt, Germany.

“All stations and the briefing room, we’ve just had loss of signal at the expected time,” said Sylvain Lodiot, Rosetta’s spacecraft operations manager at ESOC. “This is another outstanding performance by flight dynamics, so we’ll be listening for the signal from Rosetta for another 24 hours, but we don’t expect any.

“This is the end of the Rosetta mission. Thank you, and goodbye,” Lodiot said as he signed off the mission control voice loop.

The final views recorded by Rosetta peered inside an open pit named Deir el-Medina, after a noted archaeological site in Egypt. Scientists believe the depression, the size of a football stadium, is a source of jets of dust and vapor triggered as warming rays of sunlight waste away the walls of the pit.

Scientists believe the Deir el-Medina pit, and other similar sites on the comet, may form through collapses like a sinkhole on Earth. Pictures captured by Rosetta from far way revealed the walls of the pits have lumpy scale-like “goose bump” features that might be left over from the building blocks of the comet.

Rosetta’s guidance computer commanded the spacecraft’s gyroscope-like reaction wheels to deftly point the probe’s camera toward the pit before settling on a spot adjacent to Deir el-Medina.

Holger Sierks, the OSIRIS camera’s principal investigator from the Max Planck Institute for Solar System Research in Germany, displayed images on ESA’s live webcast as soon as analysts received and processed them.

He said the views were “super-duper,” showing rubble at the bottom of the Deir el-Medina pit likely left there as the basin’s walls eroded.

Rosetta was also measuring the density of the comet’s tenuous atmosphere — scattered molecules of dust and gas — on the way down, according to Kathrin Altwegg, principal investigator for the ROSINA instrument from the University of Bern.

“We will understand how dust is accelerated” from the comet, Altwegg said.

The images and data packages were compressed to maximize the scientific return in Rosetta’s final hours. There was no opportunity to store measurements for later downlink to Earth.

The spacecraft was loaded with commands to turn off its radio transmitter once it touched the comet’s surface to keep the vehicle stable and comply with regulations from the International Telecommunications Union, freeing Rosetta’s frequency for future deep space missions.

Officials decided to end Rosetta’s mission at the end of September, before the spacecraft and comet 67P pass behind the sun as viewed from Earth. That event, known as a superior conjunction, would have interrupted communications with Rosetta.

(Source: Astronomy Now)

 

PS.

Comets and the Asteroids provide useful scientific information about the creation of the solar system. They contain the original material that made up our planets and satellites. According to a theory the Comets brought water to planet Earth at the formation of our planet and other organisms such as carbon and iron which are essential for life as we know it.  

The material which existed at the creation of our solar system including our Sun were in fact inside a Star which exploited in a supernova. Therefore, we are made of Star matter.   

GM

 


 

Evidence of flowing water on Mars

 

Liquid water runs down canyons and crater walls over the summer months on Mars, according to researchers who say the discovery raises the odds of the planet being home to some form of life.

The trickles leave long, dark stains on the Martian terrain that can reach hundreds of metres downhill in the warmer months, before they dry up in the autumn as surface temperatures drop.

Images taken from the Mars orbit show cliffs, and the steep walls of valleys and craters, streaked with summertime flows that in the most active spots combine to form intricate fan-like patterns.

Scientists are unsure where the water comes from, but it may rise up from underground ice or salty aquifers, or condense out of the thin Martian atmosphere.

“There is liquid water today on the surface of Mars,” Michael Meyer, the lead scientist on Nasa’s Mars exploration programme, told the Guardian. “Because of this, we suspect that it is at least possible to have a habitable environment today.”

The water flows could point Nasa and other space agencies towards the most promising sites to find life on Mars, and to landing spots for future human missions where water can be collected from a natural supply.

Some of the earliest missions to Mars revealed a planet with a watery past. Pictures beamed back to Earth in the 1970s showed a surface crossed by dried-up rivers and plains once submerged beneath vast ancient lakes. Earlier this year, Nasa unveiled evidence of an ocean that might have covered half of the planet’s northern hemisphere in the distant past.

But occasionally, Mars probes have found hints that the planet might still be wet. Nearly a decade ago, Nasa’s Mars Global Surveyor took pictures of what appeared to be water bursting through a gully wall and flowing around boulders and other rocky debris. In 2011, the high-resolution camera on Nasa’s Mars Reconnaissance Orbiter captured what looked like little streams flowing down crater walls from late spring to early autumn. Not wanting to assume too much, mission scientists named the flows “recurring slope lineae” or RSL.

Researchers have now turned to another instrument on board the Mars Reconnaissance Orbiter to analyse the chemistry of the mysterious RSL flows. Lujendra Ojha, of Georgia Institute of Technology in Atlanta, and his colleagues used a spectrometer on the MRO to look at infrared light reflected off steep rocky walls when the dark streaks had just begun to appear, and when they had grown to full length at the end of the Martian summer.

Writing in the journal Nature Geosciences, the team describes how it found infra-red signatures for hydrated salts when the dark flows were present, but none before they had grown. The hydrated salts – a mix of chlorates and percholorates – are a smoking gun for the presence of water at all four sites inspected: the Hale, Palikir and Horowitz craters, and a large canyon called Coprates Chasma.

“These may be the best places to search for extant life near the surface of Mars,” said Alfred McEwen, a planetary geologist at the University of Arizona and senior author on the study. “While it would be very important to find evidence of ancient life, it would be difficult to understand the biology. Current life would be much more informative.”

The flows only appear when the surface of Mars rises above -23C. The water can run in such frigid conditions because the salts lower the freezing point of water, keeping it liquid far below 0C.

“The mystery has been, what is permitting this flow? Presumably water, but until now, there has been no spectral signature,” Meyer said. “From this, we conclude that the RSL are generated by water interacting with percholorates, forming a brine that flows downhill.”

John Bridges, a professor of planetary science at the University of Leicester, said the study was fascinating, but might throw up some fresh concerns for space agencies. The flows could be used to find water sources on Mars, making them prime spots to hunt for life, and to land future human missions. But agencies were required to do their utmost to avoid contaminating other planets with microbes from Earth, making wet areas the most difficult to visit. “This will give them lots to think about,” he said.

For now, researchers are focused on learning where the water comes from. Porous rocks under the Martian surface might hold frozen water that melts in the summer months and seeps up to the surface.

Another possibility is that highly concentrated saline aquifers are dotted around beneath the surface, not as pools of water, but as saturated volumes of gritty rock. These could cause flows in some areas, but cannot easily explain water seeping down from the top of crater walls.

A third possibility, and one favoured by McEwen, is that salts on the Martian surface absorb water from the atmosphere until they have enough to run downhill. The process, known as deliquescence, is seen in the Atacama desert, where the resulting damp patches are the only known place for microbes to live.

“It’s a fascinating piece of work,” Bridges said. “Our view of Mars is changing, and we’ll be discussing this for a long time to come.”

 

===================================================================

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Stargazers across the UK have observed a blood red "supermoon" in the skies above Britain for the first time in 30 years.

This phenomenon occurs when the moon is at perigee, its shortest distance from the Earth which is 226,000 miles away and consequently appears 14% larger and 30% brighter than when it is at its furthermost point. The last time this coincided with a lunar eclipse, when the moon is covered by the Earth's shadow, was in 1982 and the event will not be repeated until 2033.

During a lunar eclipse, the moon turns a deep rusty red, due to sunlight being scattered by the Earth' atmosphere.

The eclipse began to unfold from 1.10am in the UK, with the "total" phase - when the moon is completely in shadow - lasting from 3.11am to 4.24am.

 

================================================================

 

Pluto has mountains, smooth surface and an area that looks like a heart

Pluto: Ice Mountains Pluto: Ice Mountains, New Horizons - NASA
Pluto: Smooth surface Pluto: Smooth surface, broken up in sections, no sign of craters, New Horizons - NASA
Pluto: Ice Mountains, New Horizons - NASA
Pluto: Photo taken by New Horizons - NASA

 

 

 

 

 

 

 

 

 

 

 

A spectacular solar system

 Pluto finally gives up some of its secrets

The New Horizons space probe having travelled for 9.5 years at speeds of 30,000 miles per hour has now reached Pluto and has send us amazing photos and details of Pluto until recently the 9th planet of the solar system and the farthest from our Sun. Pluto is some three billion miles away and is situated in the so called Kuiper Belt (objects orbiting the Sum beyond the planet Neptune).

The pictures which we received so far have given us information which from an Astronomical perspective is extremely exciting. We can see Ice Mountains of several thousand metres high. Equally, there are smooth areas on the surface without any sign of craters. Mountains plus smooth surface indicate that the planet has been and possibly still is geologically active. The landscape of Pluto is estimated to be some 100 million years old which in geological terms is fairly new bearing in mind the solar system was formed some 4.5 billion years ago. We do not yet know what causes Pluto and its close moon Charon to be geologically active.

The diameter of Pluto has now been calculated as 2,366 km which is considerably smaller than our Moon of 3,474 km.

Pluto has 5 moons: Charon the biggest and closest, Styx, Nix, Kerberos and Hydra. The close Charon and Pluto form what is known as a binary system i.e.  these objects orbit one another and the centre of gravity is outside these bodies and is located in a location between them.  

Pluto average surface temperature is –229 C. Its atmosphere consists of nitrogen, Carbon monoxide and methane. However, bearing in mind its small size the atmosphere can only be very thin. The close proximity of Charon also means that some of its thin atmosphere maybe lost in space due to the gravitational pull of Charon and some of the particles in the atmosphere would land on Charon.

The whole astronomical world is full of excitement at the moment. We expect to receive data from New Horizons for several months and these data may force us to rethink our model of planetary formation.

I confess I have never seen Pluto through my telescope because it is too far away. To see Pluto one requires to take pictures of the area in which Pluto is situated over several days or weeks or months and then contrast the images taken.  If you see a tiny object moving in the pictures that would be Pluto. This was essentially the method used by the American Astronomer Clyde Tombaugh when he discovered Pluto in 1930.

Even the most powerful telescope will not be able to show any surface details of the planet hence the incredible success of the New Horizons probe. 

The heart shape on the south of Pluto (see picture) has now been named Tombaugh Region in honour of the discoverer of Pluto. Two ounces of his ashes have been placed in a canister inside the probe. So part of Clyde Tombaugh has travelled to the planet that he discovered. I am sure that such a gesture would have made him very happy.

There is a lot of science and thinking to do over the coming months and years and any new findings will be reported in Henley-Times.

Anyone interested in Astronomy please contact me. You could come with me to meetings/lectures of the Stratford-upon-Avon Astronomical Society and even join me on clear nights to do some astronomy using my telescope. Experience at this point is not essential as long you have a real interest in Astronomy.

 

gsmafea@outlook.com

078 5075 6522

 

 

 

===================================================================

Voyager 1 space probe entered the interstellar space



Voyager 1 has now left the Solar System to boldly go where no manmade object has gone before. It is now in a region of space that it is not affected by our Sun or any other star which is known as interstellar space. Scientists reported that their measurements changed suddenly and decisively and are now receiving data that are different and exciting. The Voyager 1 probe was launched in September 1977 and sent fantastic pictures of Jupiter and some of its moons and that of the intricate rings of Saturn. The probe contains a disc carrying images and sounds from Earth including greetings in 55 Languages and the song of a humpback whale in case alien contact is made.

 

 

Mars had a fresh water environment which would have been hapitable had life been present in it.

Report from NASA

 

Hi, I'm Joel Hurowitz, a scientist with the surface sampling system team and this is your Curiosity rover report.

 

This week the Curiosity science team released its initial findings from its first ever drilled sample on Mars. This sample was collected from the "John Klein" drill site, which is located about 500 meters east of where we  landed about 7 months ago.

 

Curiosity obtained her first drill sample and passed that sample on to her onboard analytical lab instruments, called CheMin and SAM. These powerful instruments tell us about what minerals are present in these rocks and whether they contain the ingredients necessary to sustain life as we know it.

What the Curiosity team has found is incredibly exciting. When we combine what we have learned from our remote sensing and contact science instruments with the data that's coming in from CheMin and SAM, we get a picture of an ancient watery environment, which would have been habitable had life been present in it.

As an example, the information that we're getting from the CheMin instrument, tells us that the minerals that are present in this lakebed sedimentary rock at John Klein are very different from just about anything we've ever analyzed before on Mars. And they tell us that the John Klein rock was deposited in a fresh water  environment.

 

This is an important contrast with other sedimentary environments that we've visited on Mars, like the Meridiani Planum landing site where the Mars Exploration Rover, Opportunity, has been operating since 2004.

At that site, the sedimentary rocks record evidence of an environment that was only wet in a very intermittent basis, and when it was, the waters that were there were highly acidic, very salty, and not favorable for the survival of organic compounds.

This is in direct contrast to the fresh water environment we're seeing here at the John Klein Site.

 

The SAM instrument is telling us that these rocks contained all of the ingredients necessary for a habitable environment. We found carbon, sulfur and oxygen, all present and a number of other elements in states that life could have taken advantage of.

All in all, these few tablespoons of powder from a Martian rock have provided the Curiosity science team with an exciting new dataset that tells us that Gale Crater, and perhaps all of Mars, contained habitable environments. This is an incredible success for the Curiosity mission to Gale, and the science team is looking forward to digging deeper into Mars' ancient watery past in the weeks, months, and years ahead.

 

 

 

 

 

 

 

 

News from Mars 

 

 

Bluish-Black rock with white crystals on Mars 

 

 

How could one see our good and beautiful planet Earth from space?

 

I recall some 15 years ago I was observing the moon with a small telescope and I was making some notes. Suddenly I saw a shadow moving across the face of the moon. I was startled for a second or two when I realised that shadow was our planet Earth. I had witnessed a partial eclipse. It was a wow moment for me. I saw with my own eyes the shadow of our planet, our world where we all live and yes it was round.  Prof. Carl Murray come to talk to us at the Stratford Astronomical Society about the images of Saturn from the Cassini spacecraft that has been orbiting around Saturn for a number of years. It was a very interesting talk but what actually struck me was when he pointed to what appeared to be a small faint star which could be seen through a gap in the rings of Saturn and explained that was a photo of earth from Saturn at a distance of around one billion kilometres. When one sees our good old blue planet earth from space and one reflects that everything that we know past and present and what will be in the future will take place on that planet then everything is put in the right perspective including the significance of everything. Our priority should be to work together to maintain our planet in good working order because our existence depends on it. Equally, we should protect all life that exists on our planet because everything is interdependent. Wars and anger and negative feelings are all counterproductive and useless. Below, I include some pictures of our planet, our home from space. Reflect in what you see.

 

 

 

Earth as seen from the Moon at a distance of 250,000 miles approx. The blue colour is created from our seas.

 

Photo from the Appolo programme - NASA

 

 

Earth and Moon from Mars distance 130,000,000 miles approx.

 

Photo: NASA

 

 

Earth from Saturn distance 750,000,000 miles approx.  

 

Photo NASA

Useful Link:

 

 

Stratford-upon-Avon Astronomical Society Web: www.astro.org.uk

 

Editor: George Matheou

 

Copyright: George Matheou