Your Questions / Answered
"Where and when can I see the northern lights or aurora borealis?"
,
This is one of the most common questions posted by visitors to the SunEarthPlan! If you want to see some of the answers posted in response, click on the "view all questions" link below.
You might also be interested in some of the following articles within this site.
The Northern Lights: How are scientists trying to find out what causes the most intense aurora?
Aurora Alert!: Find out how Lanacster University's AuroraWatch scheme can help you see the aurora from the UK
Seeing the northern lights from Britain: Can it be done?
Man Made Aurorae: Is it possible to create aurora at the flick of a switch?
Extra-Terrestrial Aurora: Do other planets have aurora?
"What is a star made out of?"
Josie, Morecambe
A star is a gigantic ball of plasma, or gas with electrically charged particles freely moving within it.
The main element in stars is hydrogen. Our Sun is roughly made out of 90% hydrogen, 9% helium, and then traces of other elements.
Dr. Nicolas Labrosse, University of Wales Aberystwyth
"If a typical star can only ‘burn’ up to iron before it colapses on it’s self, how large does a star need to be to ‘burn’ up to plutonium or are the elements only produced during supernova?"
Philip, Derby
Stars make energy by fusing hydrogen to make helium. Late in their life, they fuse helium to make carbon. More massive stars continue producing energy by fusion making heavier and heavier elements, up to iron. Beyond iron the process doesn’t release energy.
So where do the heavier elements come from? Mostly they are made as a side effect of other processes in stars, processes that produce neutrons. Light elements capture these neutrons then undergo radioactive (beta) decay making heavier elements.
Stars like our sun do this slowly at the end of their lives making all the elements from iron to bismuth. In supernovae these and even heavier elements (like plutonium) can be made by a more rapid burst of neutrons.
Jamie Gilmour, SEAES, University of Manchester
"We want to visit Iceland this year to possibly see the northern lights. When is the most likely time of the year to see them and can anyone predict if they are more likely to appear at any particular time?"
Jenny, Leicester
This is one of the most common questions posted by visitors to the SunEarthPlan! If you want to see some of the answers posted in response, click on the "view all questions" link below.
You might also be interested in some of the following articles within this site.
The Northern Lights: How are scientists trying to find out what causes the most intense aurora?
Aurora Alert!: Find out how Lanacster University's AuroraWatch scheme can help you see the aurora from the UK
Seeing the northern lights from Britain: Can it be done?
Man Made Aurorae: Is it possible to create aurora at the flick of a switch?
Extra-Terrestrial Aurora: Do other planets have aurora?
"Is the Sun a star?"
Ron, Liverpool
The short answer is "yes"!
In fact, it's a pretty average star - the only reason is seems so different to the other stars we can see from Earth is that it's so close by.
The Sun is "only" about 150 million kilometers away from the Earth. At this distance it only takes light just over 8 minutes to get from the Sun to the Earth.
The next nearest star, Alpha Centauri, is 4.3 light years away. This means that it takes light 4.3 years to get to the Earth from Alpha Centauri. That's why Alpha Centauri appears to be a tiny pin prick of light in the sky even though it's about the same size as the Sun - it's over a quarter of a million times further away!
Dr. Jim Wild, Lancaster University
"How long does it take for a light ray to travel from the Sun to the Earth?"
Mary, Alabama, USA
Light travels at about 300,000 km per second. That's fast! For comparison, at full speed Concorde flew at only about 0.75 km per second. Still, by Earth standards, the Sun is a long way away - about 150,000,000 km away (to place this in context, the distance between London and New York is about 5550 km).
Beacuse of the huge distance, it takes a finite amount of time - just over 8 minutes - for light to get from the surface of the Sun and travel across space to reach the Earth. So when we look up at the Sun in the sky, we're not actually seeing the Sun as it appears now, we're looking at the light that left the Sun just over 8 miniutes ago!
Dr Jim Wild - Lancaster University
Page 1 of 4
