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Astronomers have captured(捕获) the first direct image of a planet being born.
Adam Kraus, of the University of Hawaii’s Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-million-yea-old star about 450 light years from Earth.
The planet itself, based on scientific models of how planets form, is believed to have started taking shape about 50,000 to 100,000 years ago.
Called LkCa 15b, it’s the youngest planet ever observed. The previous record holder was about five times older.
Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet. Kraus presented the discovery Wednesday at NASA’s Goddard Space Flight Center in Maryland.
Observing planets while they’re forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away.
Planets can change orbits(轨道) after forming, so it’s difficult to answer such questions by studying older planets.
“These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now,” Kraus said.
Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮强过) them. Kraus and Ireland used two techniques to overcome this problem.
One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion(扭曲) created by the Earth’s atmosphere. The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors. The combination of these techniques allowed the astronomers to obtain high-quality images that let them see the planet next to the bright star.
The star LkCa 15—the planet is named after its star—was the team’s second target. They immediately knew they were seeing something new, so they plan to gather more data on the star.
1.The research on younger planets helps scientists _____________.
A. study why planets change orbits after forming
B. understand how planets move around their stars
C. answer questions about the age of stars and planets
D. know the relationship between planets and their stars
2.Why are young planets like LkCa 15b hard to discover?
A. Their stars are brighter than them.. B. They are very far from the earth.
C. They are generally too small. D. They rarely form.
3.According to the text, Kraus and Ireland _____________.
A. have been working in the same university
B. observed the planet on a volcano in Hawaii
C. used two new methods in the observation
D. cut holes in the mirrors when observing
4.Which of the following would be the best title for the text?
A. Youngest planet seen as it’s forming.
B. Planet 450 light years away discovered.
C. World’s first direct image of a planet taken.
D. New technique helps discover young planets.
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Astronomers have captured(捕获) the first direct image of a planet being born.
Adam Kraus, of the University of Hawaii’s Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-million-yea-old star about 450 light years from Earth.
The planet itself, based on scientific models of how planets form, is believed to have started taking shape about 50,000 to 100,000 years ago.
Called LkCa 15b, it’s the youngest planet ever observed. The previous record holder was about five times older.
Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet. Kraus presented the discovery Wednesday at NASA’s Goddard Space Flight Center in Maryland.
Observing planets while they’re forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away.
Planets can change orbits(轨道) after forming, so it’s difficult to answer such questions by studying older planets.
“These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now,” Kraus said.
Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮强过) them. Kraus and Ireland used two techniques to overcome this problem.
One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion(扭曲) created by the Earth’s atmosphere. The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors. The combination of these techniques allowed the astronomers to obtain high-quality images that let them see the planet next to the bright star.
The star LkCa 15—the planet is named after its star—was the team’s second target. They immediately knew they were seeing something new, so they plan to gather more data on the star.
1.The research on younger planets helps scientists _____________.
A. study why planets change orbits after forming
B. understand how planets move around their stars
C. answer questions about the age of stars and planets
D. know the relationship between planets and their stars
2.Why are young planets like LkCa 15b hard to discover?
A. Their stars are brighter than them.. B. They are very far from the earth.
C. They are generally too small. D. They rarely form.
3.According to the text, Kraus and Ireland _____________.
A. have been working in the same university
B. observed the planet on a volcano in Hawaii
C. used two new methods in the observation
D. cut holes in the mirrors when observing
4.Which of the following would be the best title for the text?
A. Youngest planet seen as it’s forming.
B. Planet 450 light years away discovered.
C. World’s first direct image of a planet taken.
D. New technique helps discover young planets.
查看习题详情和答案>>
Astronomers have captured(捕获) the first direct image of a planet being born.
Adam Kraus, of the University of Hawaii’s Institute for Astronomy, said the planet is being formed out of dust and gas circling a 2-million-yea-old star about 450 light years from Earth.
The planet itself, based on scientific models of how planets form, is believed to have started taking shape about 50,000 to 100,000 years ago.
Called LkCa 15b, it’s the youngest planet ever observed. The previous record holder was about five times older.
Kraus and his colleague, Michael Ireland from Macquarie University and the Australian Astronomical Observatory, used Keck telescopes on Mauna Kea(a volcano on the island of Hawaii, US) to find the planet. Kraus presented the discovery Wednesday at NASA’s Goddard Space Flight Center in Maryland.
Observing planets while they’re forming can help scientists answer questions like weather planets form early in the life of a star or later, and whether they form relatively close to stars or father away.
Planets can change orbits(轨道) after forming, so it’s difficult to answer such questions by studying older planets.
“These very basic questions of when and where are best answered when you can actually see the planet forming, as the process is happening right now,” Kraus said.
Scientists hadn’t been able to see such young planets before because the stars they’re circling around outshine(光亮强过) them. Kraus and Ireland used two techniques to overcome this problem.
One method, which is also used by other astronomers, was to change the shape of the telescope mirrors to remove light distortion(扭曲) created by the Earth’s atmosphere. The other method they used, which was unique, was to put masks with several holes over most of the telescope mirrors. The combination of these techniques allowed the astronomers to obtain high-quality images that let them see the planet next to the bright star.
The star LkCa 15—the planet is named after its star—was the team’s second target. They immediately knew they were seeing something new, so they plan to gather more data on the star.
1.The research on younger planets helps scientists _____________.
A. study why planets change orbits after forming
B. understand how planets move around their stars
C. answer questions about the age of stars and planets
D. know the relationship between planets and their stars
2.Why are young planets like LkCa 15b hard to discover?
A. Their stars are brighter than them.. B. They are very far from the earth.
C. They are generally too small. D. They rarely form.
3.According to the text, Kraus and Ireland _____________.
A. have been working in the same university
B. observed the planet on a volcano in Hawaii
C. used two new methods in the observation
D. cut holes in the mirrors when observing
4.Which of the following would be the best title for the text?
A. Youngest planet seen as it’s forming.
B. Planet 450 light years away discovered.
C. World’s first direct image of a planet taken.
D. New technique helps discover young planets.
查看习题详情和答案>>
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下面文章中有5处 需要添加小标题。请从(A、B、C、D、E和F)中选出符合各段意思的小标题,选项中有一项是多余选项。
A.Make a list of obstacles and benefits of achieving your goal
B.Enlist the help of others
C.Learn what you need to learn
D.Visualize yourself having achieved each of your goals
E.Get organized and reward yourself each step of the way
F.Put your goals in writing
The goals that guide us
“Not all who wander are lost,” they say, but for the great majority of us, having a road map for the future is a key element to well-being and success, however we choose to define it.This means setting goals for ourselves, and finding ways to achieve them.If you’re a wanderer, it might be time to realize the great significance of setting goals.
It’s simply a fact: when people have goals to guide them, they are happier and achieve more than they would without having them.It’s a brain thing.Achieving a goal you’ve set produces a neurotransmitter (神经传递素) responsible for feelings of pleasure, which will then activate neural circuitry that makes you eager to pursue new challenges.
Of course, a thousand mile journey starts with the first small step.And whether we’re starting on the long journey of a mid-life career switch or the walk to the bedroom to finally organize that closet, it can be hard to gather up the motivation to make that initial step.While setting goals is in itself motivating, sometimes it’s just not enough.Here are some tried-and-true ways you can begin to move toward achieving your goals.
1.
The act of writing down what you are going to do is a strong motivator.Writing down goals prevents you from leaving your goals vague.Be specific.Use action verbs.Let your goals have measurable outcomes.Specify completion dates.Also record what your reward will be for achieving the goal.Make a contract with yourself, then read it each morning and night.This will help you to be more committed to your goal as each day passes.And while you’ve got the pen in your hand...
2.
Think of everything that might stand in your way.Then decide what you can do about each obstacle.Design a plan to reduce the influence of each obstacle and increase the chances that you will be successful in reaching your goal.Knowing exactly what you will gain from reaching your goal is a strong motivator.Keeping my checkbook balanced will give me more spending money on the weekends.Walking a mile every morning will help me stay focused at work.
3.
If information or skill is keeping you from achieving your goals, determine ways to fill in the gaps, and build this into your action plan.Be willing to study and work hard to reach your goals.Think about how much time and effort will be required, and ask yourself whether you are really willing and able to do what is necessary.It is better to adjust your goals or your timetable than to proceed with a plan that is unrealistic.
4.
Find someone, a coworker or friend, with whom you share a common goal.Get someone to go to the gym with you, or to quit smoking with you, or to share healthy meals with you.A partner can help you stay committed and motivated.Look for role models, people who have already achieved the goals you seek to reach.Ask them for advice and suggestions.Find how they got where they are, and incorporate what you learn into your plan.
5.
The more real you can make your visualization, the better.Find a quiet place, visualize, and write down your experiences afterward.Go through magazines and cut out pictures that represent your goal, then put them around the house.Provide constant reminders to yourself about what you’re working towards.Describe your ideal life in the future.Write a few paragraphs describing what you have accomplished, and how your life is better as a result.Use the present tense as if it is happening right here, right now.This is another way of making your vision real.