Night Skies: July - when the Earth is furthest from the Sun

Night Skies: July – when the Earth is furthest from the Sun

Martin Lunn, of Earby Astronomical Society, tells us what to look out for in the skies in July.

THIS is the month when the Earth is furthest from the Sun. Mars will likely be at its closest to us. The Summer Triangle is now overhead and there is an eclipse of the Moon.

Mars will likely be at its closest since 2003 which was the 12 months when the Earth and Mars had been the closest that they had been in 60,000 years. This month it is going to be barely additional away at 35.7 million miles. Mars will seem as a shiny pink spot in the south and will likely be troublesome to overlook, being so shiny in the sky that it’s going to even outshine Jupiter. It is not troublesome to see why individuals dwelling 1000’s of years in the past named it the God of War.

Astronomers utilizing telescopes all the time anticipate these shut encounters to allow them to attempt to take a look at the floor of Mars in additional element. The huge drawback they face is that as Mars will get nearer to the Sun the warmth causes huge mud storms on the pink planet, making giant components of the planet invisible. This is precisely the case at the second as NASA’s Opportunity rover is in the center of one in every of these huge storms. There is numerous concern amongst the scientists that the storm will blow mud onto the photo voltaic panels which might trigger the batteries on Opportunity to go flat and finish the mission. This is a risk, however keep in mind that when Opportunity landed in January 2004 it was scheduled to have a 90 day mission time, and 14 years on it is nonetheless going.

Following on from June’s lengthy days, the nights in July are slowly turning into darker, though that won’t actually be noticeable till the finish of the month. The Summer Triangle stars of Vega, Deneb and Altair at the moment are at their greatest.

If you look straight overhead the shiny star you see is Vega, in the constellation of Lyra the Lyre, which is a small however distinctive constellation. Look to the left of Vega and you will notice the star Epsilon Lyrae which is the well-known double star. Normal sighted individuals on a transparent evening ought to be capable of see that the star is made up of two stars aspect by aspect. In a telescope every of the parts is itself a double star so we might discuss with it as a ‘double double’ or quadruple star.

The remainder of Lyra is made up of a quadrilateral of stars with Beta, at the backside proper of the quadrilateral, being a variable star that was found to fluctuate by the deaf astronomer John Goodricke in York in 1784.

Deneb is the brightest star in Cygnus the Swan, typically known as the Northern Cross. The stars are unfold out over a a lot bigger space and are fainter than in Lyra however after getting situated Cygnus it is going to be simply recognised in the future. It lies in the milky method so there are lots of stars to see on this a part of the sky and thru binoculars you may see numerous extra stars. At the finish of the cross form is the star Beta Cygni or Albireo. When seen by binoculars or a small telescope it seems as one in every of the most superb wanting double stars, made up of a blue star and a yellow star.

The third member of the summer time triangle is the most southerly; Altair, in the constellation of Aquila the Eagle. The constellation does give the slight look of an eagle in the sky. It has, like Vega, a reference to York, as a result of the star Eta is variable and was found by Edward Pigott who labored in York with John Goodricke.

Both Beta Lyrae and Eta Aquilae had been found on September 12th 1784, an evening I typically discuss with as a ‘evening to recollect’ so far as astronomy is involved. In reality Goodricke and Pigott contributed a lot to variable star astronmy in the temporary time they labored collectively from 1781 till 1786 that I discuss with them as ‘the fathers of variable star astronomy’.

The Summer Triangle exhibits us that appearances might be misleading. When we have a look at the three stars that type the triangle, Vega seems a lot the brightest, Altair and Deneb showing considerably fainter, however when we contemplate how distant they’re a unique image seems. Altair is a mere 17 mild years away, Vega a barely extra distant 25 mild years, however Deneb, which seems the faintest, is 2,500 mild years away. This implies that in the event that they had been all positioned the similar distance from the Earth, Deneb would massively outshine the different two stars.

Another shiny star that may be seen in the summer time months, this time very low down in the south, is Antares in the constellation of Scorpius the Scorpion, typically often called ‘the rival of Mars’ due to its color. Unfortunately, as a result of Antares is so low in the sky when seen from from Britain, it by no means rises excessive in the sky. To see it at its greatest you’d must be in the Mediterranean space. It is a pink tremendous large and actually so huge that the orbits of the 4 planets closest to the Sun; Mercury, Venus, Earth and Mars, would comfortably match inside Antares.

At the second as a consequence of its closeness to us Mars seems a lot the brighter than its ‘rival’ Antares in the southern sky. Apart from Antares, the remainder of the southern sky is made up of huge faint teams of stars.

With regards to the extra acquainted teams of stars in the sky, the Plough is nonetheless excessive in the north west, which implies that the ‘W’ of Cassiopeia has now grow to be just a little greater in the north east.

The planets in July

I’ve already indicated that Mars will grow to be very noticeable in the south japanese sky from about 11pm onwards. In the south west the shiny white spot you will notice in the sky is Jupiter, the largest planet in the photo voltaic system. Jupiter has been seen in the evening sky for many of the 12 months however is now starting to look barely decrease in the sky in the south west. Jupiter will nonetheless be seen all by July however will grow to be a lot decrease in the sky, particularly as we method the finish of the summer time months. Located halfway between Jupiter and Mars is the well-known ringed planet Saturn which seems as a unclean yellow shiny ‘star’ low in the sky.

Just as the Sun units, look low to the west and you will notice the brightest planet in the evening sky:Venus, or ‘the night star’ because it is typically known as. The different bare eye planet, Mercury, is very near the horizon this month so you’d be unlikely to see it.

Meteor Showers

The solely meteor bathe this month is the Delta Aquarids, these meteors or taking pictures stars as some individuals name them are the stays of comet Macholz. The bathe’s most will likely be on the evening of July 30 when usually round 15 meteors per hour might be seen, however this 12 months, with the most being near the full moon, the sky will likely be shiny making it tougher to see these meteors.

Phases of the Moon for July

Last Quarter 6; New Moon 13; First Quarter 19; Full Moon 27.

There will likely be an eclipse of the Moon on the night of the 27th . An eclipse of the Moon happens when the Moon passes into the shadow of the Earth. The Moon has no mild of its personal, however we see it as a result of it displays daylight that hits it. We might say that moonlight is merely mirrored daylight. When the Moon passes into the shadow the direct daylight is reduce off, however mild nonetheless reaches the Moon by passing by the environment of the Earth and being bent, or ‘refracted’, onto the floor of the Moon. The Earth’s environment will block off the blue mild so most of the mild that reaches the Moon will likely be pink, therefore the Moon will grow to be a coppery pink color, or as some individuals name it a ‘blood moon’.

The eclipse will start when the Moon is nonetheless under the horizon as seen from Britain. When the Moon rises in the south east sky at eight.47pm it would already be in eclipse and can seem reddish and fairly darkish as a result of it is so low in the sky. The eclipse will finish at 10.13 pm when the Moon will likely be nonetheless be low in the sky.

The full moon in July is often called the Thunder Moon as this is the month of the 12 months when we’re most probably to get thunder storms.

On July 6, the Earth will likely be at Aphelion, or furthest level from the Sun on its annual path, when it is going to be 95 million miles from the Sun. We are at Perihelion, or closest level to the Sun, in January when the Earth is round 91 million miles away. It is the tilt of the Earth that determines which season we’re in, relatively than our distance from the Sun. In July the northern hemisphere is tilted in the direction of the Sun therefore now we have summer time, whereas in January the northern hemisphere is tilted away and we expertise winter.

The Earby Astronomical Society will likely be taking its summer time break from conferences now which implies that the subsequent assembly will likely be on Friday September 29 at All Saints’ Church, Earby, from 7.30pm-9pm pm. The speaker will likely be Martin Lunn MBE FRAS, Earby Astronomical Society, and the title of the discuss will likely be ‘The Autumn Sky’. Everyone is welcome.

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