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Earth from Space、。。
By Discovery & National Geographic Ch 。。

The Earth gravitationally interacts with other objects in space, especially the Sun and the Moon. During one orbit around the Sun, the Earth rotates about its own axis 366.26 times, creating 365.26 solar days, or one sidereal year. the Earth's axis of rotation is tilted 23.4° away from the perpendicular of its orbital plane, producing seasonal variations on the planet's surface with a period of one tropical year (365.24 solar days). The Moon is the Earth's only natural satellite. It began orbiting the Earth about 4.53 billion years ago (bya). The Moon's gravitational interaction with the Earth stimulates ocean tides, stabilizes the axial tilt, and gradually slows the planet's rotation ..

The Earth's internal heat comes from a combination of residual heat from planetary accretion (about 20%) and heat produced through radioactive decay (80%). The major heat-producing isotopes within the Earth are potassium-40, uranium-238, uranium-235, and thorium-232. At the center, the temperature may be up to 6,000 °C (10,830 °F), and the pressure could reach 360 GPa. Because much of the heat is provided by radioactive decay, scientists postulate that early in the Earth's history, before isotopes with short half-lives had been depleted, the Earth's heat production would have been much higher. This extra heat production, twice present-day at approximately 3 byr, would have increased temperature gradients with radius, increasing the rates of mantle convection and plate tectonics, and allowing the production of uncommon igneous rocks such as komatiites that are rarely formed today ..

Earth and Earth Sciences Documentaries 、。。

Earth from Space ..
By Discovery & National Geographic Ch ..

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LESA ร่วมมือกับ โรงเรียนนายเรืออากาศฯ​ ทดสอบการปล่อย CubeSat จาก Drone และบั้งไฟ

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LESA Thai Sounding Rocket (บั้งไฟ)

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NASA's Sounding Rockets 、。。
ScienceCasts 、NASA's Sounding Rockets 、。。
A Great 10 Minutes in Space 、。。
By By science@nasa 、。。

Sounding rocket missions can often be the key to getting a quick answer to a tightly focused science question 、。

The spectacle of a mammoth rocket ‘breaking the surly bonds of Earth’ takes our breath away .. Equally amazing are the secrets revealed to us by science missions these rockets have launched – and NASA puts careful thought into what kind of mission will best achieve that science .. Sometimes a large, multi-instrumented mission on a giant rocket is the best way to go .. But other missions are better suited to a smaller, less expensive rocket as the key to getting a quick answer to a tightly focused science question .. Like a sounding rocket .. A sounding rocket is an instrument-carrying rocket designed for research, such as taking measurements and performing scientific experiments during a sub-orbital flight 、。。

Kristina Lynch, Professor of Physics at Dartmouth College says, “A sounding rocket experiment can be designed in six months. From proposal acceptance through data analysis, a mission can be done in 1-3 years, as opposed to many more years for a typical satellite mission .. The trade-off is that you only get 10 minutes in space – but, as my colleagues in the sounding rocket community say, "It’s a great 10 minutes” 、。。

Sounding rockets afford a certain amount of flexibility. Because they can be launched from temporary sites all over the world, sounding rockets can be used for remote field studies .. They can also be used to develop and test new scientific instrumentation for use in more costly, longer duration orbital missions. And because of their low cost and short lead time, sounding rocket missions are perfect for use by university graduate students, particularly to gather data for PhD dissertations 、。。

Sounding rockets are especially well suited for studying areas of the Earth’s upper atmosphere inaccessible by orbital missions, providing the only way to directly sample the lower portion of near-Earth space with scientific probes .. Furthermore, they are ideally suited to position an experiment for an up-close look at auroras – beautiful green curtains of light that sometimes dance across the night sky 、。。

While auroras can be wondrous to behold, they are sparked by geomagnetic storms with potential side-effects such as satellite malfunctions and power outages. Telecommunications, air traffic, power grids, and Global Positioning System signals are vulnerable .. So, understanding this layer of near Earth space is vital 、。。

Lynch says, “Sounding rockets are used to get above the part of Earth’s atmosphere where we live and breathe .. Above 60 miles (100 km), the atmosphere includes an electrically charged gas where charged particles flit around, collide, respond to magnetic and electric fields, and produce an aurora .. These ‘northern and southern lights’ appear flame-like, but the movement looks slower than that of a flame, and their structure can be more orderly .. We want to understand this movement and structure. Is the movement fast or slow? Why? Where is it going?” 、。。

Lynch is working on a sounding rocket mission that could provide some answers. ISINGLASS, short for Ionospheric Structuring: In Situ and Ground-based Low Altitude StudieS, launched on March 2 and is one of about 20 sounding rockets that NASA will be launching in 2017 、。。

ISINGLASS deployed an array of payloads launched by a single rocket to take measurements at several locations in an aurora simultaneously .. Understanding what the aurora’s visual patterns signify within the aurora itself can serve as an analog to help scientists understand what’s happening farther out, even extending this information to auroras on other planets 、。。

All it takes … is “a great 10 minutes.” 、。。

Note :-
Kristina Anne Lynch 、。。
Professor of Physics and Astronomy
Undergraduate Advisor 、。。

Kristina Lynch is an experimental physicist specializing in the plasma physics of the auroral ionosphere. She has been at Dartmouth College since 2002 .. Her undergraduate degree was from Washington University in St Louis (1984) .. After this she spent four years at the Air Force Geophysics Laboratory in Massachusetts, working on the CRRES satellite .. She did her graduate work at the University of New Hampshire (PhD in 1992) working on auroral sounding rockets .. From 1992 to 2002 she worked at the UNH Space Science Center on sounding rockets and the European Cluster satellite project .. She is a member of the American Geophysical Union 、。。

For more news about science in and around Earth’s atmosphere, stay tuned to

NASA Sounding Rocket Program Handbook 、。。

Solar System Documentary 、Collection 、。。

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Drop CanSat from Drone. 
5 Photos - View album

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LESA ทดสอบการส่ง CanSat ด้วยบั้งไฟ Thai Sounding Rocket 
16 Photos - View album

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Dealing with Space Debris 、。。
By ESA 、。。

Earth is surrounded by a cloud of space debris .. This material ranges from dead satellites and rocket stages to fragments of material and even flecks of paint and all this junk could do enormous damage to working satellites 、。。

During 18–21 April, experts from around the world will meet at ESA’s European Space Operations Centre, Darmstadt, Germany for the 7th European Conference on Space Debris 、。。

Delegates will discuss the extent of the debris problem and what can be done to ensure that satellites we rely on – providing us with services such as navigation, TV and weather forecasting – can operate safely in the future 、。。

Talks will address acute issues like current practices in debris avoidance, novel concepts for removing debris, and the deployment of large constellations of several thousand satellites for telecommunications 、。。

The conference will be opened by ESA Director General Jan Woerner and NASA’s former orbital debris chief scientist, Donald Kessler 、。。

On 18 April and 21 April, live webcasts will cover the keynote address and press briefing, respectively. Details via 、。。

More information 、。。
ESA Space Debris 、。。
ESA CleanSpace 、。。

Space Debris .. Interagency Report on Orbital Debris .. 1995 、。。

Space Debris .. Detecting, Tracking and Imaging Space Debris 、。。

Earth 、Earth Sciences & The Space Debris Documentaries 、。。

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Readying the Webb Telescope for Launch、。。
ScienceCasts 、Readying the Webb Telescope for Launch、。。
By science@nasa 、。。

The most sophisticated space science telescope ever constructed – the James Webb Space Telescope (JWST) – is targeted to launch in October 2018 .. With a primary mirror three times as wide as The Hubble Space Telescope and a special sensitivity to penetrating infrared radiation, Webb will peer into the far reaches of the universe to reveal how the first stars and galaxies formed after the Big Bang 、。。

Stringent testing is underway to prove it can handle an Earth-shaking take-off and still capture the universe’s first light while deeply ensconced in the hyper-cold of space. At NASA’s Goddard Space Flight Center in Greenbelt, MD engineers are testing Webb’s science payload in special facilities simulating launch vibration and noise 、。。

Eric Smith is the JWST Program Director/Program Scientist. “This is the most dynamically complex large telescope ever subjected to vibration tests by NASA. The telescope must deploy in a precisely synchronized sequence as the temperature drops to near absolute zero on its journey to L2.” 、。。

“Webb has many interconnected parts of different stiffnesses. All those parts – including the folded, stowed instruments and mirrors – have to survive launch at room temperature. These elements must then all come together seamlessly in extreme cold to form perfect optical images. All materials change shape as they cool. A flower blossom, a marshmallow, even some metals, will shatter or break if hyper-frozen and dropped onto a hard surface or bent.” 、。。

“All of Webb’s components, once assembled, must cool and move in precisely the right way so that the ultra-fine optical tolerances are met when everything is cold. Think of being able to repeatedly parallel park your car and know the position of your back bumper to within a 10th of a diameter of a human hair. That’s how accurate we must be in knowing the position of our mirror surfaces.” 、。。

To make this happen, Webb was vibration tested at Goddard, and it will undergo cryogenic testing at Johnson Space Center in Houston, TX. Cryogenic testing involves taking the entire telescope and instrument package to a temperature of approximately 40 degrees above absolute zero – that’s a very chilly minus 388 degrees Farenheit (minus 198 degrees Celsius) - and making sure its components work as predicted. The science instruments, mirror segments, and mirror base structure were cold-tested previously. At Johnson, the whole assembly – instrument module plus mirrors -- will be cryogenically tested together for the first time 、。。

Upon proving that it’s up to cold snuff, Webb’s science section will travel to a Northrop Grumman facility in Redondo Beach, CA for attachment to the spacecraft bus and sunshield. After further vibration and acoustic testing, it’s off to French Guiana for launch atop an Ariane 5 rocket 、。。

“Seeing our hopes realized in intricate, awe-inspiring hardware is thrilling. Of course, the ultimate goal of the mission is not the hardware itself but the knowledge it will return. We are just now beginning to once again reach out to the science research community for their ideas of what to observe with Webb, and that is the most exciting part by far!” 、。。

For more news about NASA’s next great space telescope, stay tuned to

Solar System Documentary 、Collection 、。。

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ScienceCasts 、Close Approach Comets 、。。
ScienceCasts 、Close Approach Comets 、。。
By science@nasa 、。。

Comets are some of the most interesting objects in the solar system .. Water that filled the ancient oceans of Earth might have been delivered by comets . And there is growing evidence that many comets (as well as some primitive asteroids) contain molecules key to life .. NASA has sent space probes to travel hundreds of millions of miles to study these icy interlopers from the outer solar system 、。。

Comets are balls of frozen gases, rock and dust that orbit the sun .. Jets of gas and dust from comets form long tails that can be seen from Earth when they fly close enough to our planet 、。。

In 2017 and 2018, three comets will pass near the Earth 、。。

Their names are 41P/Tuttle-Giacobini-Kresak, 45P/Honda-Mrkos-Pajdusakova, and 46P/Wirtanen. Astronomers call them “41P”, “45P”, and “46P”, for short 、。。

At closest approach on April 1, 41P was only 56 times farther from Earth than the Moon. 45P was even closer at 31 lunar distances when it flew by on February 11 .. And 46P approaches 30 lunar distances, on December 16, 2018 、。。

Kelly Fast, Program Manager in the Near-Earth Object Observations Program at NASA Headquarters says, “This provides a good opportunity to do science without having to launch a spacecraft.” 、。。

Telescopes around the world have been trained on the comets as they pass by, studying their structure and chemical compositions 、。。

For the general public, comet 45P was an easy target for small telescopes when it passed closest to Earth in February, and 41P will be an easy telescope target through May of 2017 .. But 46P will be the biggest attraction. In December 2018, it could be visible to the naked eye from dark sky sites 、。。

Astronomer Tony Farnham of the University of Maryland says, “46P has a small nucleus, but is known to be a ‘hyperactive’ comet. It is probably ejecting ice crystals from its surface, producing higher than normal activity.” 、。。

This hyperactivity may contribute to the naked-eye brightness of 46P. It also makes the comet somewhat unpredictable with unexpected surges in activity—and visibility—possible as it passes by 、。。

These comets have been so close that amateur astronomers can help study them, too .. Farnham is assisting Nalin Samarasinha at the Planetary Science Institute in Tuscon, Arizona with the organization of the “4*P Coma Morphology Campaign” to coordinate the efforts of amateurs worldwide 、。。

“Amateur astronomers can help us monitor these comets without interruption,” explains Farnham .. “With observers distributed around the world, we can get much better coverage, with fewer and shorter breaks.” 、。。

“We can then combine amateur observations with observations from professional telescopes to study the structures in the comet’s atmosphere—or ‘coma.’ If we use the amateur data in our studies, then they get to be an author on any papers that result.” 、。。

“A few years back, we used this same type of network for our studies of comet ISON, and they proved very successful, with data from 23 different groups around the world.”

For more about objects in and around Earth’s neighborhood, stay tuned to

Solar System Documentary 、Collection 、。。

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What's Up for May 2017 、。。
by Jane Houston Jones from NASA's Jet Propulsion Laboratory in Pasadena、California 、。。

This month, Jupiter is well placed for easy evening viewing, Saturn rises before midnight, and the moon dances with Venus, Mercury and Mars 、。。

What's Up for May .. Jupiter at its best, Saturn rises in the late evening sky, and the moon dances with the planets ..

Jupiter climbs higher in the southeast sky earlier in the evening this month. This means that telescope viewers don't have to wait until midnight to get good views of the planet. You can enjoy Jupiter through binoculars, too .. Through binoculars, you should be able to see Jupiter's four Galilean moons: Io, Europa, Ganymede and Callisto and watch them change position from night to night ..

Our moon appears near Jupiter from May 5-8. The moon joins Venus and Mercury in the eastern sky just before sunrise on May 22 and 23. And it pairs up with red Mars just after sunset in the west-northwest sky on May 26 ..

Saturn is now visible before midnight, rising around 11:30 p.m. in early May and by 9:30 p.m. later in the month. The best time to see Saturn is when it is highest in the sky. That's after midnight this month, before midnight in June, and by early evening in July. Through your telescope you may see some of Saturn's cloud bands and even a glimpse at Saturn's north polar region, so beautifully captured by NASA's Cassini spacecraft ..

Keep up with all of NASA's missions at

NASA 、What's Up Next 、。。

Jane Houston Jones 、。。
Random thoughts about LA and the rest of the universe 、。。

The Story of the Solar System 、。。
By Mark A. Garlick 。。

Solar System Documentary 、 Collection 、。。
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