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It is solstice time.  The reason for the season is axial tilt and today our position on our orbit around the sun has aligned the earth's axis so the North Pole is pointing in the opposite portion of t

Earth and moon from 40 million miles distant. Taken by the OSIRIS-REx, an asteroid-hunting space craft moving away from us at nearly 20,000kph...  

Space X Falcon 9 in 4K.  Full screen needed.   

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As is probably obvious I gain huge pleasure from heading out with a pair of binoculars or a telescope and looking out at the stars and planets visible in the night sky.

Jupiter and Saturn are clear and visible in the early night at the moment and I had the pleasure of seeing Saturn's moon Titan for the first time a few nights ago - it only took half a century plus or minus a bit!

My ambition is to get a really good astro-photograph of Saturn hanging delicate in a field of stars ... though that will probably take a couple of years of effort!

I'm very very much an amateur astronomer, but the brilliance of the astronomical community is that amateur observations can still matter.

Not that long ago an amateur astronomer called Gennady Borisov was taking photographs with a 0.65m telescope out in war torn Crimea and he noticed a tiny spec was moving when he overlaid multiple nightly images. He noted it down as gb00234 and reported its location to the astronomical community, who reacted with interest given the object's unusual position well above the ecliptic - the reasonably flat disc where most planets and asteroids orbit the sun.  Soon bigger telescopes were brought to bear, trundling around on their bearings to the correct declination and right ascension reported by Mr Borisov.  And these bigger telescopes saw a comet, with a dim tail of gas evaporating off the central nucleus.  The comet was named C/2019 Q4 (Borisov) in honour of its discoverer! 

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In the early 1600s, Johannes Kepler was the first person to realise that observations of orbiting bodies fitted to an elliptical curve and to work out how to fit the observations to their one unique conic curve as they travelled under the influence of gravity; and when astronomers did these calculations they got a bit of a shock.

Rather than predicting a standard elliptical orbit for a planet, comet or asteroid repeatedly orbiting around the sun, the calculations predicted a hyperbolic trajectory.  This object was zooming in from interstellar space, its path scarcely changed by the sun's gravity, before flying off and away back into the interstellar void.

anim_orbit_c2019q4borisov.gif

It is only the second time in all of history we have knowingly seen such an object.  In 2017 the interstellar comet/asteroid Oumuamua zipped through the solar system creating much delight, and queries whether it was an alien space ship - especially when it accelerated away from the solar system!

Luckily this time we've caught the object early in its entry of the solar system - Oumamua was only seen when it had already started to leave.

However C/2019 Q4 (Borisov) is really screaming through - Oumanua has an eccentricity of 1.2, while Q4 is hyperbolic to an eccentricity of over 3.  It is really moving.

Predictions have been made that at any one moment at least one interstellar object should be passing through the solar system, but being able to see and observe them is a huge challenge.  It was down to the patience of amateurs like Mr Borisov, quietly filling in the observational gaps left by the huge professional telescopes zoomed in to image tiny fields of view.

Expect lots of telescope time to be booked to watch Q4's majestic sweep and exit from our tiny stage.

Sadly Q4 is unlikely ever to be bright enough for me to see it - my telescope is too small, but over the next few weeks its trajectory will be pinned down with ever greater accuracy and maybe we will be able to back calculate and work out where it came from with some vague accuracy.

Just think, billions of years ago some orbital catastrophe jettisoned a comet from its home star system, leaving it travelling the interstellar void.  Now after billions up billions of kilometers of travel it is going to grace our solar system for a month or so, before travelling on and on through the galaxy.

It is quite a feat to have been able to see and understand just what Q4 is.  I hope we learn much more in the next few weeks, all from dots on photographic images, and the spectrum of light reflected back from our sun warming an object which hasn't felt the warmth of a star for many many ions.  Just think on that.

 

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  • 2 months later...

Not quite sure if I approve of all the Low Earth Orbit Constellations being mooted as solutions to giving everyone high speed mobile internet.  I'm sure it'll make Manxy have paroxysms, but I'm more concerned about space debris and ruining the night sky for astronomers.

 

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9 hours ago, Chinahand said:

Not quite sure if I approve of all the Low Earth Orbit Constellations being mooted as solutions to giving everyone high speed mobile internet.  I'm sure it'll make Manxy have paroxysms, but I'm more concerned about space debris and ruining the night sky for astronomers.

 

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Saw the Starlink satellites going across yesterday morning and again today. Pretty incredible sight.  So many of them!   If you haven’t seen them yet, Sunday morning will hopefully be clear. Set your alarm...

https://www.heavens-above.com/AllPassesFromLaunch.aspx?lat=54.2361&lng=-4.5481&loc=Isle+of+Man&alt=0&tz=GMT

 

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21 minutes ago, ed fournier said:

Saw the Starlink satellites going across yesterday morning and again today. Pretty incredible sight.  So many of them!   If you haven’t seen them yet, Sunday morning will hopefully be clear. Set your alarm...

https://www.heavens-above.com/AllPassesFromLaunch.aspx?lat=54.2361&lng=-4.5481&loc=Isle+of+Man&alt=0&tz=GMT

 

I thought satallites were supposed to be in geostationary orbit?

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1 hour ago, GD4ELI said:

Not at all. Check out LEO, MEO and HEO orbits.

Aren’t they Donald Duck’s nephews?

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