Posts Tagged ‘NASA’

Is this a picture of Earth?

March 21, 2012
One of these images is a photograph of the Earth. The other isn't. So which is which? And what is the other one? (Images courtesy of NASA)

One of these images is a photograph of the Earth. The other isn't. So which is which? And what is the other one? (Images courtesy of NASA)

Friends. Fellow humans. We live on an amazing planet. And I feel priveliged to belong to the first generation in all of Earth’s history who have seen our planet as viewed from space. As we beat ourselves up for our collective failure to safeguard our planet, I feel it is worthwhile to pause and realise just how recently we acquired a truly global perspective.

The image on the left is a photograph of the Earth taken on a Hasslebad camera by an astronaut on Apollo 17 who, 28,000 miles out from Earth, looked out the window and happened to find the Earth illuminated fully. Since you can see Antarctica in daylight you can tell this must be in the southern hemisphere summer. When the camera was returned to Earth, the film was developed and the image revealed – there were no digital previews in 1972!

The image on the right is a fabrication. It uses ‘data’ acquired by a low Earth orbit satellite (Suomi) which is cleverly pasted together as described here.

Illustration of the way in which the right hand image was fabricated

Illustration of the way in which the right-hand image was fabricated. Despite being acquired by a satellite at a height of around 300 miles, it simulates the view from much further away. Image courtesy of NASA.

So what do we conclude? The view is no less amazing for having been simulated. And the whole Earth perspective it represents is as much a philosophical perspective as a physical one. But despite the ubiquity of a similar image as the default iPhone desktop, I find the original more emotionally powerful. The fact that an individual human being took the picture on the boldest adventure of a generation somehow resonates with me.

The six and a half minute video below describes in more detail how the images are made – it is shockingly complicated. Enjoy 🙂

http://www.sciencefriday.com/embed/video/10425.swf

My big problem with astronomy

February 22, 2012
Pretty Galaxy

A Pretty Galaxy - the subject of erudite speculation by astronomers and mindless reporting by hacks. The circle marks the apparent location of a black hole called HLX-1. Don't believe the colours - the picture is 'data' and not a photograph. The galaxy - which is inferred to be spiral in shape even though we see it edge on - is called ESO 243-49

Recent stories in Wired and The Register illustrate perfectly everything I hate about popular astronomy. First of all, you can see these are both routine hacks by comparing them with the press release.

Don’t get me wrong: I am filled with admiration for astronomers: their instruments are astounding; the maths and physics of observing is inspiring; and of course the Universe is just breathtakingly beautiful. What irritates the pants off me is the ridiculous desire to ‘explain’ what they observe. What we end up with is a pretty picture and a fantastical, unverifiable ‘sciency’ tale. Frankly we would be better of with just the pretty picture and good old fashioned ‘fairy’ tale.

To explain what I mean I have reproduced extracts from the ‘Wired’ article below in blue with what the article should (IMHO) have said.

Wired: The Hubble space telescope has spotted a supermassive black hole floating on the outskirts of a large galaxy.
Actual: Scientists looking at data from the Hubble Space Telescope have inferred the existence of a black hole near a large galaxy.(How?)

Wired: The location is odd because black holes of this size generally form in the centers of galaxies, not at their edges. This suggests the black hole is the lone survivor of a now-disintegrated dwarf galaxy.
Actual: The location is odd because evidence indicates black holes of this size are generally  found near the centers of galaxies, not at their edges. Scientists don’t understand this.

Wired:The black hole — named HLX-1 — is 20,000 times more massive than the sun, and is situated 290 million light-years away at the edge of the spiral galaxy ESO 243-49.
Actual: The black hole — named HLX-1 — is estimated to be 20,000 times more massive than the Sun (how?), and is estimated to be 290 million light-years away at the edge of the spiral galaxy ESO 243-49

Wired: Hubble detected a great deal of energetic blue light coming from the black hole’s accretion disk — a massive collection of gas and dust that spirals into the black hole’s maw, generating x-rays. But scientists studying Hubble’s data also noticed the presence of cooler, red light, which shouldn’t have been there.
Actual: Hubble detected blue light  and red light. They inferred that the blue light came from an accretion disk. But they couldn’t understand the red light.

Wired: Astronomers suspect the red light indicates the existence of a cluster of young stars, roughly 200 million years old, orbiting around the black hole. These stars, in turn, are the key to explaining the chaotic history of the supermassive black hole.
Actual: Astronomers could explain the red light if there were young stars orbiting around the black hole. They even thought up a story about these unobserved stars that might actually exist.

Wired: HLX-1 was likely formed at the center of a dwarf galaxy that once orbited ESO 243-49. But in this dog-eat-dog universe of ours, large galaxies often swallow up their smaller brethren. When the dwarf galaxy came too close to ESO 243-49, the larger galaxy plucked away most of its stars, leaving behind the exposed central black hole. The force of the galaxies’ collision would have also triggered the formation of new stars, explaining the presence of a young stellar cluster around the black hole. The cluster’s age, 200 million years, gives a good estimate of when the merger occurred. HLX-1 may now be following the same fate as its parent galaxy, slowly getting sucked into ESO 243-49. But researchers don’t know the details of the black hole’s orbit, so it could also possibly form a stable orbit around the larger galaxy, circling as the isolated reminder of a vanished dwarf.
Actual: HLX-1 was likely formed when a space dragon called PTMD-X1 laid an egg, which grew into a blue headed X-ray dragon. Astronomers speculate that the dragon’s mother died when it was just 200 million years old  causing the youngster to cry tears which then turned into stars through a process astronomers call tear-star -formification. The blue colour of the stars shows the dragon was sad and astronomers hope that it is happier now and has made friends.

One small ringtone for man…

September 26, 2011
NASA Logo

NASA Logo

After having visited NASA last week, I noticed that it is now possible to download ‘sounds of NASA‘ as ring tones, including some of the most famous sound bites. For example

The NASA home page has lots of other links you may enjoy too. Strangely, they didn’t have ‘May the Force be with you’.

Meeting one’s heroes

September 26, 2011
Michael and Jonathan at NASA Glenn

My colleague Jonathan Pearce and I at the NASA Glenn Research Centre

I have just returned from an exhausting trip to the NASA Glenn Research Center in Cleveland, Ohio. Staff there had sought out someone to teach them how to ‘measure the temperature’, and settled on NPL: What an endorsement! And representing NPL were myself and my colleague Jonathan Pearce. We worked night and day for weeks beforehand to prepare the course and then had an exhausting three days teaching and talking about temperature measurement, but the staff at NASA seemed happy, so I guess it was worth it in the end.

Beforehand I was terrified. In my mind NASA represented the ultimate in technological capability and I was anxious that we simply wouldn’t be able to answer their questions. Rationally I knew that Jonathan and I are pretty expert at what we do, but that didn’t stop me being scared – especially at the start. But it quickly transpired that although the people on the course were very expert in their fields too, they appreciated a little clarification about some subtleties of temperature measurement. In short, the people at NASA were not ‘super beings’ but instead they were just like myself, and Jonathan and our colleagues at NPL.

NASA is an awesome organisation which is having some difficulties at the moment. According to recent testimony to Congress by  the first Man on the Moon, Neil Armstrong, NASA has rather lost its way.

In summary, some significant progress has been achieved during the past year. However, NASA, with insufficient resources, continues to try to fulfill the directives of the Administration and the mandates of the Congress. The result is a fractious process that satisfies neither. The absence of a master plan that is understood and supported by government, industry, academia and society as a whole frustrates everyone. NASA itself, riven by conflicting forces and the dashed hopes of canceled programs, must find ways of restoring hope and confidence to a confused and disconsolate work force. The reality that there is no flight requirement for a NASA pilot-astronaut for the foreseeable future is obvious and painful to all who have, justifiably, taken great pride in NASA’s wondrous space flight achievements during the past half century.

Winston Churchill famously stated: “The Americans will always do the right thing after they have exhausted all the alternatives”. In space fight, we are in the process of exhausting alternatives. I am hopeful that, in the near future, we will be doing the right thing.

I obviously don’t have Neil Armstrong’s insight, but I think perhaps his perspective is a little distorted. He was after all a single individual who was carried aloft at the pinnacle of a stupendous technological enterprise costing 4% of the Gross Domestic Product of the USA*. And now I think perhaps he is being a little hard on his colleagues who are having to cope in more humble roles and in less affluent times. I recognised many phenomena at NASA because similar changes have affected NPL. The people at both organisations are being urged to do more with less, and to do work which is ‘more relevant’. On the ground, this can be personally difficult for committed staff who find themselves working with ever diminishing resources, and fewer and fewer  colleagues. And in the background there is still the glow of the glory days which will never return.

It’s always difficult when one meet’s one’s heroes. Visiting NASA I found out that my heroes were not ‘super beings’ , but real human beings. And since their achievements are the achievements of real human beings, I find them even more admirable. ‘NASA, you’re still my hero.’

*For comparison NPL costs roughly 0.003 % of UK GDP.

NASA Celebrates Earth Day

April 26, 2011
NASA image of the Lena Delta

NASA image of the Lena Delta. Click for larger image.

Satellite imagery has transformed our conception of our planet, and I consider that a blessing. Because of the images we have seen, it is now undeniable that everyone on Earth shares something, even if it is only the atmosphere. Perhaps this single, barely-definable, change of consciousness will in the end prove to be NASA’s greatest achievement.

Anyway. To celebrate Earth day – which I have to confess passed me by – NASA have compiled 70 photographs in a slide show. You can download all the pictures in high resolution and many of them are breathtakingly beautiful. Take a look – it is worth a moment or two of anyone’s time. I chose the picture above because of the abstractness of the pattern, which could have been a micrograph, but in fact shows a river delta. Click to enlarge the picture and just gaze at our planet in wonder.

The big picture

April 8, 2011
A low pressure area in the northern hemisphere.

A low pressure area in the northern hemisphere: Click on the image to enlarge it - its worth it. Courtesy NASA Earth Observatory.

This photograph was taken from the cupola of the International Space Station and shows a VAST low pressure area, across the eastern Pacific ocean. What strikes me about this view is the beautiful spiral pattern which has formed. And yet, on the ground at each location within the picture, there would be no evidence of the  vast spiral formation of which the local weather was just a small component.

And this seems to be a metaphor for what we seek in our effort to understand Earth’s climate. We are searching for the abstract perspective that would reveal specific patterns in otherwise apparently random weather.

That’s all – its time for bed. Read here for more detail about the picture on NASA’s Earth Observatory.

Looking at the Sun…

March 5, 2011
Collage of Solar Images from NASA Solar Dynamics Observatory

Collage of Solar Images from NASA Solar Dynamics Observatory. Click to enlarge.

Warning: Never  look directly at the Sun. Even without a telescope or binoculars the intensity of direct Sunlight is sufficient to damage your eyes.

For most astronomical activities, it is a problem to collect enough light to create an image of a distant object. For solar astronomy the problem is quite the opposite: the problem is to block out the phenomenal glare in order to see the details of the solar surface. This week in Protons for Breakfast we contrasted the size of the Earth with the size of the Sun – and every time I re-visit that comparison I am boggled and humbled. And so perhaps it was that which caused me to notice this story on the Register about scientists having begun to understand why the current cycle of sunspots had got off to such a slow start. The story has also been covered slightly more soberly by Scientific American

The Sunspot Cycle is intriguing in itself, but because it weakly affects the amount of solar radiation reaching the Earth, it is also important for calculations about the possible extent of Global Warming. The story led me to look at NASA’s Solar Dynamics Observatory, and I would urge you to take a look too. I found it astonishing to see something as familiar as the Sun is this new way. After the Four minute Introductory Movie try these links or search for your own favourites.

Pages on NASA’s Solar Dynamics Observatory


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