Science is great. We think we have a problem solved, all the loose ends tied up, and then up pops a new discovery. Some see this as evidence of science’s fragility. Of course those people don’t understand the scientific method. In science, nothing is sacred, nothing is sacrosanct, everything is open to new data.
The latest episode to remind us of the power of the scientific method involves the Man on the Moon – the dark region known as Procellarum that is easily visible from Earth. As one of many Lunar Maria, we automatically thought it formed the same way as the other Maria – a late giant impact broke through the surface and cause lava to flow up, which then cooled as the dark material we see. But new data obtained by NASA’s GRAIL mission reveals that the Procellarum region likely arose not from a massive asteroid strike, but from a large plume of magma deep within the moon’s interior.
Scientists have created a map of the Procellarum, and found that its border is not circular, but polygonal, composed of sharp angles. These could not have been created by a massive asteroid. Instead, it is more likely that these were produced by giant tension cracks in the moon’s crust as it cooled around an upwelling plume of hot material from the deep interior. As cracks occurred, they formed a “plumbing system” in the moon’s crust through which magma could meander to the surface.
So it turns out that we were right about the lava flow part, but at least for this Maria, we were probably wrong about how the lava came up.
A great chance to see so much tonight. Look west at sunset to see the lazy crescent moon, lying on its back. You simply can’t miss Jupiter nearby because it’s the brightest starlike object in the evening sky – brighter than any star. Now look to the left – see three stars in a line that make up Orions’s belt. Between the moon and Orion you’ll see a set of stars in a V shape. They make up the face and horns of Taurus the bull. The brightest star of that V is Aldebaran- the eye of the bull – a star in the twilight of its life. Now the hardest part. Look right of the moon and Jupiter and you see a small fuzzy blob called Pleiadas, one of the few constellations where the stars are actually close to each other in space. The Pleiades star cluster is composed of hundreds of stars that were born out of the same vast cloud of gas and dust in space. The Pleiades stars are still moving together through the galaxy. If you have binoculars, use them to get a better view of the Pleiades cluster. It won’t be much longer before Pleiades drops out of the evening sky.
A wonderful opportunity to recognize celestial objects far and near.
The most expensive part of space travel is having to bring all our fuel with us. This means we have to launch everything from Earth. Imagine there was no such thing as a gas station, instead we would all have to drive to the oil field in our own fuel tankers and collect all the car fuel required for the rest of our life! Clearly we need gas stations in space, and the Moon might be able to play that role.
To this end, Australian researchers have developed a substance that looks and behaves like soil from the moon’s surface and can be mixed with polymers to create ‘lunar concrete’, a finding that may help advance plans to construct safe landing pads and mines on the moon. Valuable rare earth minerals, hydrogen, oxygen, platinum and the non-radioactive nuclear fusion fuel Helium-3 (He-3) are abundant on the moon. NASA and other space agencies have shown interest in lunar mining but the US is yet to ratify a 1984 treaty that would strictly regulate moon resource extraction.
However, even if moon mining was allowed, lunar conditions are so different to Earthly conditions that new machinery may have to be invented to develop resources found there. Furthermore, the cost of transporting materials made on Earth would be prohibitive, forcing scientists to come up with ways to build certain equipment using material only found on the moon’s surface. So the long journey to the outer reaches of the solar system goes via the moon, but it starts with recreating the moon on Earth.
Did you see the moon last night! Northern spring is a great time to look at the moon as you easily see the phenomena of earthshine. The bright crescent of the moon is reflected sunlight. But the dark part of the moon, the part that should be in shadow, is very bright over the next few nights. This is lit up by light reflecting from Earth back onto the moon in a phenomena known as earthshine. It is also known as the Moon’s ashen glow or as the old Moon in the new Moon’s arms.
We’ve known about this for a long time. Leonardo da Vinci sketched the crescent Moon with earthshine as part of his Codex Leicester, written between 1506 and 1510. Recently it has taken on a new level of importance in the study of global warming. The amount of earthshine is a proxy for the amount of the earth’s reflectance, known as its albedo. And this is directly related to the amount of clouds in the atmosphere. So the scientists at big bear solar observatory have an ongoing project measuring the amount of earthshine each night.
So have a look up tonight and see if you can spot earthshine.
I could never hope to put together words that describe the beauty and majesty of a solar eclipse. As the moon blocks out the sunlight, your skin crawls. For just a moment (2 mins 40sec) all the rest of world seems not to matter. Everything falls away and you finally really see the Sun. Everything falls away and you feel small, scared and entirely insignificant.
Now, If you live on mainland USA, consider how lucky you are. First, the moon and earth are the only two bodies in the solar system of exactly the right size and distance apart to create a total eclipse. Second, the moon is gradually moving away from the earth. Several tens of thousands of years ago, the moon was too close and so too large in the sky. Several tens of thousands of years from now it will be too far away and too small in the sky. Third, most solar eclipses occur over the sea or in places difficult to reach ( and expensive). But in 2017 all you have to do is pop a tent in your car and drive. Go see this event. It will stick in your mind for the rest of your life and you too will struggle for words to describe it.
The most frustrating aspect of exploring the solar system is that it can be expensive. Not really expensive when compared to many other things we pay for, but still expensive. This has lead us to go down the safe path of super missions- big but infrequent and very safe missions to explore very specific questions. Maybe this will all change though.
Cubesats are the new tool for the exploratory mind. Instead of doing a few big missions, why not do lots and lots of small missions? Cubesats are small, cheap and quiet reliable. We can get loads of data from lot of points, and who cares if one or two fail- we would still have hundreds. So what can we do with these shoe boxed sized satellites. Well, why not send a bunch to the moon. There is loads of science to be done at our nearest neighbor, and it serves as a great proof of concept for going further afield. What else could we do with a load of small individual satellites? Time to think outside the box.