Posts Tagged ‘Astronomy’
Are They Just Right? The Discovery of the TRAPPIST-1 Planetary System and Their ‘Goldilocks’ Potential
In the past several months science educators teaching astronomy and space exploration probably haven’t needed a lot to motivate science students who are endlessly fascinated with the possibility of life outside our own planet. The recent discovery of seven planets around TRAPPIST-1 (a star named for the Transiting Planets and Planetesimals Small Telescope in Chile) has provided teachers new seeds to plant into the imagination of young minds interested in exoplanetary discovery. eLibrary can help feed that imagination with loads of resources.
In May 2016 researchers in Chile reported in the journal Nature the discovery of three planets with sizes and temperatures similar to Venus and Earth orbiting around an ultra-cool dwarf star just 40 light-years away in the Aquarius constellation. Earlier this year NASA’s Spitzer Space Telescope, along with the Very Large Telescope Array at Paranal in Chile, confirmed two of those planets, and then found five more exoplanets. Of the seven, three are presently believed to fall within the habitability zone (the ‘goldilocks’ zone), that area around a star in which rocky planets may hold liquid water and harbor life.
TRAPPIST-1, the star which these planets orbit, is classified as an ultra-cool dwarf. The star is so cool that water in liquid form could exist on planets that are even closer in orbit than Mercury is to our sun. In the years to come, if further observations reveal oxygen in any of the planet’s atmosphere, which could point to photosynthesis of plants, there is a good probability life can exist on these planets.
eLibrary has recent news information on this discovery as well as Research Topics on exoplanets, habitable planets, and general information on astronomy, cosmology, and space exploration that can help your students dive deeper into the questions of life existing elsewhere in our galaxy and beyond.
Here are some things scientists know thus far about TRAPPIST-1 and its planets:
- All seven of the TRAPPIST-1 planet’s orbit is closer than Mercury’s orbit around our sun.
- TRAPPIST-1 is much cooler and redder than the sun, and only slightly larger than Jupiter, which is about a tenth of the size of the sun.
- Because the planets are so close to TRAPPIST-1, all seven planets appear to be in a gravitational lock. That is, one side of each planet permanently faces the star, just as our moon is gravitationally locked and we only see one side of it.
- One year on the closest planet orbiting TRAPPIST-1 is equal to just 1.5 earth days. The farthest planet’s yearly orbit is equal to 18.8 earth days.
- If you were standing on one of the planets, each of the other planets would appear prominently in the sky, and at times appearing much larger than the moon does in our sky.
- TRAPPIST-1 is a mere 40 light-years away. In layman’s terms, that’s still 235 trillion miles away.
Admittedly, it is hard to think of something that happened 2.8-billion years ago as “Breaking News,” but that is what astronomers are calling ASASSN-15lh. In May 2015, a new light source appeared in the skies in the Southern Hemisphere. A new supernova (ASASSN-15lh) was found as part of the All Sky Automated Survey for SuperNovae in Cerro Tololo, Chile. Astronomers believe that this is the most luminous supernova ever observed. In fact, it is so bright that it shines with the luminosity of 572 billion suns. That’s billion with a “B.” ASASSN-15lh is an exploding star that belongs to the “superluminous” class which has luminosities 10 to 100 times that of normal supernovae. A few dozen of these enormous blasts have been spotted in the past decade, but this “new” one is about twice as bright as any of them. It appears just off the Tucana constellation in the southern sky, so you have to be in the Southern Hemisphere to see it.
In the year 1006, Earthlings were startled to see a supernova with the naked eye – an exploding star so bright that it could be seen during the daytime. But don’t go out looking for ASASSN-15lh with just a pair of binoculars; this supernova is so many light years away it can only be seen with the assistance of a very large telescope.
You can search for supernovas and other out-of-this-world topics in eLibrary.
Here are just a few of our Space-related resources:
Last December NASA successfully launched the unmanned Orion Multi-Purpose Crew Vehicle spacecraft from Cape Canaveral, a test flight that lasted over four hours and two trips around the earth. NASA hopes that this maiden voyage is the beginning of what will be their next giant leap: The Journey to Mars.
First things first, however. As a precursor, NASA has developed the Asteroid Redirect Mission (ARM) where it intends to identify and redirect a near-earth asteroid in a stable orbit around the moon. In the 2020s the goal will be to send astronauts aboard Orion to explore the asteroid and bring back samples. ARM is also part of NASA’s Asteroid Initiative, which includes the Asteroid Grand Challenge, an initiative that is designed to identify and relocate potentially hazardous asteroids away from Earth. But the Asteroid Redirect Mission is clearly a stepping stone for the greatest leap that mankind has ever taken.
45 Years ago when Neil Armstrong took the first step on the Moon, it sparked the whole country’s imagination and already our thoughts had turned toward one day manning a flight to Mars. With the development and testing of Orion, that next great leap has begun. As part of the plan, NASA has begun developing technologies, such as new space suits, asteroid sampling techniques, and solar power technology to move large cargo from earth’s orbit into deep space around the moon. All these developments will help NASA make great strides toward the ultimate goal of a human expedition to Mars in the 2030s.
You can find a host of information by doing basic and advanced keyword searches for resources on specific missions to Mars, Near-Earth objects such as asteroids, and other NASA space missions, including information on NASA’s two new missions. Check out our Research Topics on the planet Mars, Mars Exploration, Mars Rover and Pathfinder Missions, and Mars Science Laboratory (Curiosity), as well as one covering asteroids.
In April 2004 NASA sent into space the Gravity Probe B satellite on a mission to prove a couple of postulations published 98 years ago this week by a man considered by many the greatest intellectual mind ever. On May 4, 2011, seven years after the probe was launched, the experiments finally confirmed two predictions by Albert Einstein‘s theory of general relativity: the warping, or curving, of space and time (space-time) around Earth; and frame-dragging, the amount of space-time that is dragged around Earth by its rotation. Thursday, March 20th, marks the landmark date when Einstein published those arguments, and others, under his theory of gravity in “The Foundation of the General Theory of Relativity.”
Even though Einstein worked these theories out mathematically, to get a practical sense of what these principles meant, there are two analogies most frequently used. First, with the warping of space-time around a large mass, imagine a large, heavy ball (representing the Sun) placed in the center of a thin, stretched sheet of rubber (representing space). The ball presses down in the middle of the sheet causing a depression, or curvature. When another smaller ball (representing Earth) is tossed onto the sheet it will circle and roll toward the larger ball. Einstein posited that gravity was not some mysterious gravitational force, as Isaac Newton thought, but merely smaller objects traveling through space along a curve toward the larger ones with enough mass that warps space around them. With frame-dragging, think of Earth as being immersed in honey. As the Earth rotates, the honey around it would swirl. And so it would with space and time.
Although measuring these two effects by the Gravity Probe B has led to practical applications in the improvement in aeronautics and GPS technologies, for astrophysicists and cosmologists it has fueled further interest in black holes. It is believed that objects with much more mass than our earth or sun can warp space-time fabric so much that they can create a hole where space itself falls into and where even light cannot escape.
Is gravity nothing more than the motion of objects around other, more massive objects which distort and curve the fabric of space-time? Are there objects so massive where even light cannot escape? To dig deeper into these questions, and more on Albert Einstein and his theory of general relativity, visit eLibrary and view the resources below.
eLibrary Browse by Topic:
The Geminids, one of the most spectacular meteor showers of the year, has its highest number of visible meteors around December 14th. However, this year’s display will be subdued for most of watching hours because of the approaching full moon on December 17th. But that shouldn’t stop you from looking for it. Even with a near-full moon, during its peak it may be possible to see over 100 meteors in an hour, and with it, maybe a few bright fireballs.
The Geminids gets its name from the Gemini constellation from where it seems to emanate, but the meteors can appear nearly anywhere in the sky. Unlike other meteor showers, the Geminids originate from the asteroid 3200 Phaethon rather than a comet.
For those of you living in the city with a considerable amount of ambient light it’s advisable to leave the city behind in order to get the full effect of the Geminids. Considering the complication of a full moon, you’ll need to wake early and rub the sleep from your eyes. The best viewing should be on the 13th and 14th of December from the time the moon sets in early morning until dawn.
The big question over the past year about Comet ISON’s potential visibility since its discovery in September 2012 has been this: will it sizzle or fizzle? When the comet was first discovered some thought it would be the “comet of the century.” Since that time, the prediction of its brightness and visibility has dimmed considerably. But most experts say that if comets are anything they are unpredictable.
Comet ISON is classified as a sungrazing comet. All comets orbit and come close to the Sun, but sungrazing comets like ISON come much closer to the Sun at perihelion (its closest point to the Sun). In fact, some come so close to the Sun that they either vaporize or they fragment and come apart. Such could be the case with Comet ISON. According to the NASA-supported Comet ISON Observing Campaign (CIOC), when Comet ISON swings around the Sun on November 28th it will be at its brightest, coming within three solar radii at perihelion. However, since it will be so close to the Sun during the daylight hours it will be invisible to the eye. Considering the unpredictability of comets, if ISON vaporizes or comes apart while making its close pass to the sun, it could all but disappear. However, if ISON vaporizes and breaks apart after it has made its pass around the sun, visibility and brightness could be better than expected. If it does neither then ISON could be fairly unremarkable.
Look for ISON in the days and weeks after its emergence from the sun on November 28th as it climbs the east-southeast sky just before dawn. In the best case scenario, you’ll be able to see ISON with the naked eye. However, you’ll probably at least need binoculars or a small telescope.
You can learn more about Comet ISON and other comets in eLibrary through research topics, publications, and other resources.
Comet Research Topics:
Other Comet ISON & general comet and astronomy resources:
Asteroid and Comet Exploration (USA in Space article)
Astronomy (Browse by Topic)
Comet (Hutchinson Encyclopedia)
Comet ISON Observing Campaign (Website)
Comets (Browse by Topic)
NASA Hubble Telescope Captures Comet ISON (NASA Website)
Science News (Publication)