The Alpha Aurigid Meteors.

The Alpha Aurigid Meteor shower occurs each year between 25 August and 6 September, peaking between 11.30 pm GMT on 31 August and 0.30 am GMT on 1 September. However the shower is notoriously hard to observe, having been recorded only in the years 1911, 1929, 1930, 1935, 1979, 1980, 1986, 1994 and 2007 (some of these observations occurred before the 'official' discovery of the shower by Cuno Hoffmeister and Artur Teichgraeber in 1935, but have subsequently been linked to the shower). The shower has its radiant (the point from which the meteors appear to radiate) in the constellation of Auriga, making it more-or-less impossible to see from the Southern Hemisphere, and only produces about six meteors per hour at its peak; though as the New Moon occurs on 30 August this year, there should be very little light interference from that source, giving astronomers in the Northern Hemisphere a chance of glimpsing these meteors.

The radiant of the Alpha Aurigid Meteors. Copper Mountain Mesa.

Meteor showers occur when the Earth crosses the orbit of a comet or similar body, encountering millions of tiny particles left behind in that body's trail, even if it is not close by itself. The Alpha Aurigid Metoers are thought to originate from the tail of the comet C/1911 N1 (Kiess). This is a Long Period Comet (comet with a period of longer than 200 years), thought to visit the inner Solar System only once every 2497 years, last having done so in August 2011, when it came to about 0.2 AU from the Earth (i.e. about 20% of the distance between the Earth and the Sun). The orbit of C/1911 N1 (Kiess) is highly elliptical, and tilted at an angle of 148° to the plane of the Solar System (or 58° with a retrograde orbit - an orbit in the opposite direction to the planets) and takes the comet from 0.68 AU from the Sun (68% of the average distance between the Earth and the Sun, slightly inside the orbit of Venus) to 367 AU from the Sun (367 times as far from the Sun as the Earth, or 20 times as far as Neptune, but within the inner part of the Oort Cloud).

 The orbit and current position of comet C/1911 N1 (Kiess). JPL Small Body Database Browser.

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The Lyrid Meteor Shower.

The Lyrid Meteors are typically visible between 16 and 25 April each year, and will be at peak visibility on the morning of Sunday 22 April in 2017. This coincides with the First Quarter Moon, also on Sunday 22 April, so viewing this year should be good. At its peak the Lyrid Meteor shower typically produces about 20 meteors per hour, though higher rates have been recorded.

Sky map showing the radiant point for the Lyrid Meteors (i.e. the point from which the meteors appear to radiate). Earth Sky.

The Lyrid Meteors are comprised of debris from the comet C/1861 G1 Thatcher (named after the astronomer A. E. Thatcher, not the politician). This is a long-period comet that spends most of its time in the Oort Cloud, only visiting the inner Solar System once every 415 years, the last occasion being in 1861. When the comet visits the inner Solar System it is heated by the Sun, melting the ices that make up its surface and releasing a trail of dust, which continues to follow the path of the comet. The Earth passes through this trail in April each year, creating a light show as the dust particles burn in the upper atmosphere which appears to radiate from the star Vega in the constellation of Lyra. 

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Comet C/2014 Q1 (PANSTARRS) reaches its perihelion.

Comet C/2014 Q1 (PANSTARRS) reached its perihelion (the closest point on its orbit to the Sun) on Monday 6 July 2015, when it was 0.31 AU from the Sun (i.e. 0.31 times the average distance at which the Earth orbits the Sun, slightly inside the orbit of the planer Mercury). Unfortunately this comet is poorly placed for observation from Earth, within 10° of the Sun observed from Earth at perihelion, and not realistically visible to Earth-bound astronomers, though it may be visible later in the year, particularly to observers in the Southern Hemisphere.

Comet C/2014 Q1 (PANSTARRS) imaged from the FRAM telescope in Mendoza Province, Argentina, in May 2015. The comet is the slightly diffuse object at the center of the frame, the linear objects are stars, elongated by their movement over the length of the exposure. Martin Mašek/Institute of Physics of the Academy of Sciences of the Czech Republic/Česká Astronomická Splolečnost.

C/2014 Q1 (PANSTARRS) was discovered on 16 August 2014 by the University of Hawaii's PANSTARRS telescope. The name C/2014 Q1 (PANSTARRS) implies that it is a non-periodic comet (C/) (all comets are, strictly speaking, periodic since they all orbit the Sun, but those with periods longer than 200 years are considered to be non-periodic), that it was the first comet (comet 1) discovered in the second half of August 2014 (period 2014 Q), and that it was discovered by the PANSTARRS telescope.

The path of C/2014 Q1 (PANSTARRS) through the inner Solar System. JPL Small Body Database Browser.

C/2014 Q1 (PANSTARRS) has a 14 400 000 yearl period and a highly eccentric orbit tilted at an angle of 43.1° to the plain of the Solar System, that brings it to 0.31 AU from the Sun at perihelion (0.31% of the distance between the Earth and the Sun, slightly inside the orbit of Mercuary) and to 2312 AU (2312 times as far from the Sun as the Earth) at aphelion. This is 77 times as far from the Sun as the planet Neptune, and 46 times as far from the Sun as the outer edge of the Kuiper Belt, but  still only touching the inner boundary of the Oort Cloud.

It is possible that C/2014 Q1 (PANSTARRS) will break up at perihelion, due to heating and tidal forces generated by the Sun, but failing which it may be possible to observe it with binoculars in the constellation of Gemini from about 15 July onwards, though it will be close to the horizon and only visible shortly after dusk. As the comet moves above the horizon later in the month it will also move closer to the moon, making it harder to observe. On 19 July the comet will pass into the constellation of Leo, and on 22 July to Sextans, which is only visible in the Southern Hemisphere. From here it will move into the constellation of Crater on 5 August, then Hydra on 18 August and Centaurus at the end of the month. It will fade throughout this period, and by the end of August a fairly good telescope will be needed to view the comet.

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Comet C/2012 F3 (PANSTARRS) reaches its perihelion.

Comet C/2012 F3 (PANSTARRS) reached its perihelion (the closest point on its orbit to the Sun) on Tuesday 7 March 2015, when it was 3.46 AU from the Sun (i.e. 3.46 times the average distance at which the Earth orbits the Sun). The comet is visible only with a fairly good telescope, and currently can be seen only from...

Comet C/2014 Q2 (Lovejoy) reaches perihelion.

Comet C/2014 Q1 (Lovejoy) reached its perihelion (the closest point on its orbit to the Sun) on Friday 30 January 2015, when it will be 1.29 AU from the Sun (i.e. 1.29 times the average distance at which the...

Comet C/2014 E2 (Jacques) makes its closest approach to Earth.

Comet C/2014 E2 (Jacques) passed the Earth at a distance of 0.56 AU (i.e. 56% of the distance between the Earth and the Sun, about 84 million km) on Thursday 28 August 2014. This is not a close approach (it is further than the distance between Mercury and the...

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When Schotz’s Star passed through the Solar System’s Oort Cloud.

It is estimated that about 30% of impact craters larger than 10 km on the Earth and the Moon have been caused by long period comets originating in the Oort Cloud (the very outermost part of the Solar System, between about 30 AU and about 120 000 AU from the Sun, which is to say between 30 and 120 000 times as far from the Sun as the Earth. In the 1980s it was theorized that the Sun could have an undetected binary companion orbiting in this part of space, which periodically triggered showers of comets to enter the inner Solar System, triggering mass-extinction events on Earth, though since that time it has become apparent that mass extinction events do not show any such regular pattern and astronomers have failed to find any such companion star.

This still leaves the possibility of close encounters with other stars, with such bodies passing through the Oort Cloud and triggering showers of comets to enter the Inner Solar System. It has been calculated that on average 12 stars pass within one parsec (208 000 AU) of the Sun every million years, one star every 9.2 million years coming within 0.25 parsecs (52 000 AU) of the Sun. Previous studies have found four stars which may in the remote future pass through the Solar System’s Oort Cloud; HIP 85605, which may come within 20 800 AU of the Sun in 332 000 years’ time (though this is highly uncertain as HIP 85605 is a poorly understood binary system whose distance and motion are poorly resolved), HIP 89825 (Gliese 710) which may reach 0.27 parsecs (56 160 AU) from the Sun 1 400 000 years in  the future, HIP 63721 which may also reach 0.27 parsecs (56 160 AU) from the Sun in 146 000 years, and HIP 89825 which may come withion 0.36 parsecs (74 260 AU) from the Sun in 1.5 million years.

In a paper published in the Astrophysical Journal Letters on 10 February 2015 and on the arXiv database at Cornell University Library on 16 February 2015, a team of scientists led by Eric Mamajek of the Department of Physics& Astronomy at the University of Rochester describe the results of a study of a newly discovered body, Scholtz’ Star (WISE J072003.20-084651.2) with the Southern African Large Telescope and Magellan Telescopes which suggest that the body may have passed through the Oort Cloud in the past.

Finder chart of 6 6 arcmin² centred on WISE J072-0846 from SuperCOSMOS Sky Surveys. Scholtz 2013.

Sholtz’s Star currently lies about 7 parsecs (light years) from Earth in the constellation of Monoceras. It is an extremely dim Red Dwarf star lying close to the Galactic Plane, and consequently was not discovered until 2013. It has a low tangential velocity (i.e. it appears not to move very much viewed from Earth), which is unusual in so close a star; all stars are constantly in motion, so if a nearby star appears stationary it is probably moving straight towards or straight away from us. A previous study has suggested that this body is in fact a binary system.

Mamajek et al. conclude that Sholtz’s Star is in fact a binary system, comprising two bodies separated by a distance of about 0.8 AU (80% of the distance between the Earth and the Sun). These bodies have masses of 86 and 65 times that of Jupiter respectively, leading Mamajek et al. to conclude that the larger body, WISE J072003.20-084651.2A (when naming bodies in other star systems stars are given upper case letters and planets lower case letters) is an extremely small Red Dwarf star, while the second body, WISE J072003.20-084651.2B, is a Brown Dwarf, a body too small to fuse ordinary hydrogen in its core, but large enough to fuse the heavy hydrogen isotope deuterium. These bodies are estimated to be about 3-10 billion years old, to have originated within the galactic thin disk (expand) and to form part of the Hercules Stream (expand).

Calculations of the motion of Scholtz’s Star suggest that the body reached a closest distance from the Sun of 0.25 parsecs, or 52 000 AU, from the Sun approximately 700 000 years ago. For comparison the current closest known star, Proxima Centuri, is 268 300 AU from the Sun, while the most distant man-made object, Voyager 1, which has been travelling outwards since 1977, is currently 130.6 AU from the Sun. Despite this close proximity Sholtz’s Star would still have been to dim to be seen by the naked eye, though it would have been brighter than ProximaCenturi. However, unlike ProximaCenturi, Sholtz’s Star is highly active, occasionally producing very bright flares, which may have resulted in it becoming dimly naked eye visible for periods of minutes or even hours.

Finder chart of 6 6 arcmin² centred on WISE J072-0846 from WISE w2-band observation.

An approach at 52 000 AU places Sholtz’s Star within the outer part of the Oort Cloud, where it may potentially have encountered and perturbed the orbits of comets orbiting our Sun, though outside the denser Inner Oort Cloud, which extends to 20 000 AU from the Sun and where the majority of such comets are found.Comets orbiting the Sun at a distance of 52 000 would have an orbital period of about 4.2 million years, thus any such bodies perturbed from their orbit’s by the approach of Sholtz’s Star would take about 2.1 million years to reach the Inner Solar System, arriving about 1 400 000 years in the future. It is estimated that in order to cause a major comet flux (in which the number of long period comets reaching the Inner Solar System increases by a factor of 10 or more), then another star would have to come within 10 000 AU of the Sun, so any flux created by the passage of Sholtz’s Star should be quite small compared to the usual rate of cometry bombardment, generated by galactic tidal effects, presenting only a very minor threat to the Earth.

Mamajek et al. also re-examined the poorly known HIP 85605, concluding that it is both brighter and further away than previously estimate. Mamajek et al. conclude that HIP 85605 is currently 60 parsecs (light years) from the Sun, and that its closest approach to our system will come in 2.8 million years’ time, when it will reach a distance of 10 parsecs (light years). This indicates that the flyby by Sholtz’s Star is the closest known encounter with the Solar System by another star at any point in the calculable past or foreseeable future.

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The discovery of a Brown Dwarf companion to the star ζ Delphini.                                       Brown Dwarfs are objects intermediate to stars and planets in size; they are not large enough to fuse ordinary hydrogen in their cores, but are large enough to fuse the heavier isotope deuterium. These objects are thought to...

Emissions from Comet C/2002 VQ94 (LINEAR).                                                C/2002 VQ94 (LINEAR) was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) team at the Massachusetts Institute of...

A small cold Brown Dwarf, 7.175 light years from Earth.                                                           Brown Dwarfs are curious objects, intermediate between stars and planets. They lack the mass to fuse hydrogen in their cores like true stars, but are massive enough to fuse deuterium (a heavy isotope hydrogen, containing one proton and one neutron in its atomic... 

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The Alpha Aurigid Meteors.

The Alpha Aurigid Meteor shower occurs each year between 25 August and 6 September, peaking between 11.30 pm GMT on 31 August and 0.30 am GMT on 1 September. However the shower is notoriously hard to observe, having been recorded only in the years 1911, 1929, 1930, 1935, 1979, 1980, 1986, 1994 and 2007 (some of these observations occurred before the 'official' discovery of the shower by Cuno Hoffmeister and Artur Teichgraeber in 1935, but have subsequently been linked to the shower), though the shower occurs between the New and First Quarter Moons this year, so it may be possible to observe it. The shower has its radiant (the point from which the meteors appear to radiate) in the constellation of Auriga.

The radiant of the Alpha Aurigid Meteors. Copper Mountain Mesa.

Meteor showers occur when the Earth crosses the orbit of a comet or similar body, encountering millions of tiny particles left behind in that body's trail, even if it is not close by itself. The Alpha Aurigid Metoers are thought to originate from the tail of the comet C/1911 N1 (Kiess). This is a Long Period Comet (comet with a period of longer than 200 years), thought to visit the inner Solar System only once every 2497 years, last having done so in August 2011, when it came to about 0.2 AU from the Earth (i.e. about 20% of the distance between the Earth and the Sun). The orbit of C/1911 N1 (Kiess) is highly elliptical, and tilted at an angle of 148° to the plane of the Solar System (or 58° with a retrograde orbit - an orbit in the opposite direction to the planets) and takes the comet from 0.68 AU from the Sun (68% of the average distance between the Earth and the Sun, slightly inside the orbit of Venus) to 367 AU from the Sun (367 times as far from the Sun as the Earth, or 20 times as far as Neptune, but within the inner part of the Oort Cloud).

The orbit and current position of comet C/1911 N1 (Kiess). JPL Small Body Database Browser.

See also...

 The Perseid Meteor Shower.

The Perseid Meteor shower lasts from late July to early September each year, and are expected to be at a peak on 12-13 August 2014, slightly after the Full Moon on 10 August, which may make the meteors harder to spot...

 The Eta Aquarid Meteor Shower.

The Eta Aquarid Meteor Shower will be at a peak on Monday 5/Tuesday 6 May 2014, with up to 45 meteors per hour at it's peak, radiating from the constellation of Aquarius. This does not spend long above the horizon in...

 The Ursid Meteors.

The Ursid Meteors are expected to peak on 22 December this year, with the shower being potentially visible to some extent between 17 and 26 December. The extent of the shower is variable, some years...

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Comet C/2014 E2 (Jacques) makes its closest approach to Earth.

Comet C/2014 E2 (Jacques) passed the Earth at a distance of 0.56 AU (i.e. 56% of the distance between the Earth and the Sun, about 84 million km) on Thursday 28 August 2014. This is not a close approach (it is further than the distance between Mercury and the Sun), but is the closest that the comet is likely to come to the Earth in the lifetime of anyone alive, as it has an orbital period estimated to exceed 21 000 years. The comet is currently visible to amateur astronomers armed with binoculars in the Northern Hemisphere, staying permanently above the horizon in the constellation of Cassiopeia. In September it will move through the constellations of Cepheus, Cygnus, Vulpecula and Sagitta, reaching Aquila on 1 October, where it will remain visible till the beginning of December.

An image of C/2014 E2 (Jacques) taken on 1 April 2014. Damien Peach/Universe Today.

C/2014 E2 (Jacques) was discovered on 13 March 2014 by Cristóvão Jacques Lage de Faria, Eduardo Pimentel and João Ribeiro de Barros working at the Southern Observatory for Near Earth Asteroids Research in Minas Gerais State, Brazil. The name C/2014 E2 (Jacques) implies that it is a non-periodic comet (C/) (all comets are, strictly speaking, periodic since they all orbit the Sun, but those with periods longer than 200 years are considered to be non-periodic), that it was the second comet (comet 2) discovered in the first half of March 2014 (period 2014 E), and that it was discovered by Jacques.

Star chart showing the position of C/2014 E2 (Jacques) in the sky as seen from Earth from May 2014 to February 2015. In the sky.

C/2014 E2 (Jacques) is calculated to have a 21 355 year orbital period and a highly eccentric orbit tilted at an angle of 156° to the plain of the Solar System (or 66° traveling in a retrograde direction) that takes it from 0.66 AU from the Sun at perihelion (66% of the distance between the Earth and the Sun, slightly inside the orbit of Venus) to 1539 AU from the Sun at aphelion, which is 1542 times as far from the Sun as the Earth, over 500 times as far from the Sun as Neptune, 300 times as far from the Sun as the outer limit of the Kuiper Belt, but still within the inner Oort Cloud.

The calculate orbit of C/2014 E2 (Jacques). JPL Small Body Database.

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 Comet C/2012 K1 (PANSTARRS) reaches its perihelion.

Comet C/2012 K1 (PANSTARRS) will reach its perihelion (the closest point on its orbit to the Sun)  on Wednesday 27 August 2014, though it will not be visible...

 Rosetta Mission rendezvouses with Comet 67P/Churyumov–Gerasimenko.

The Rosetta Spacecraft moved into position alongside Comet 67P/Churyumov–Gerasimenko on Wednesday 6 August 2014, the first spacecraft to reach a cometary target, and ten years after the mission was launched. It...

 Emissions from Comet C/2002 VQ94 (LINEAR).

C/2002 VQ94 (LINEAR) was discovered by the Lincoln...

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Emissions from Comet C/2002 VQ94 (LINEAR).

C/2002 VQ94 (LINEAR) was discovered by the Lincoln Near-Earth Asteroid Research (LINEAR) team at the Massachusetts Institute of Technology on 11 November 2002. It was originally classified as a Damocloid Family Asteroid (asteroids with eccentric, comet-like orbits that average more than 8 AU from the Sun and come no closer than 5.2 AU from the Sun), but was later reclassified as a Long Period Comet. The designation 2002 VQ94 implies the 2367th asteroid (asteroid Q94) discovered in the first half of November 2002 (period 2002 V), while C/ implies a Long Period Comet and (LINEAR) indicates the discoverer.

C/2002 VQ94 (LINEAR) has a 2875 year orbital period and an elliptical orbit tilted at an angle of 70.4˚ to the plane of the Solar System, which takes it from 6.8 AU from the Sun (6.8 times as far from the Sun as Earth, and outside the orbit of Jupiter) to 397 AU from the Sun (397 times as far from the Sun as the Earth, more than 13 times as far from the Sun as Neptune and about 8 times as far from the Sun as the outer margin of the Kuiper Belt - but still on the inner fringes of the Oort Cloud).

The calculated orbit of C/2002 VQ94 (LINEAR). JPL Small Body Database Browser.

Cometary activity was first detected from C/2002 VQ94 (LINEAR) on 28 August 2003 by David Jewitt using the University of Hawaii 2.2-m Telescope, when it was 8.9 AU from the Sun (i.e. 8.9 times as far from the Sun as Earth is). Jewitt detected a distinct cometary halo (i.e. particles being shed from the bosy) and also calculated the comet to be 40.7 km in diameter. 

Follow up observations by Pavlo Korsun and Oleksandra Ivanova of the Main Astronomical Observatory of National Academy of Sciences of Ukraine and Viktor Afanasiev of the Special Astrophysical Observatory of the Russian Academy of Sciences using the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences on 9 March 2006 confirmed that C/2002 VQ94 (LINEAR) had a cometary halo, and were able analyse this spectrographically, detecting the molecules CN, C₃, CO+, and N₂+. 

The detection of molecular emissions from bodies this distant from the Sun has only been achieved for four comets previous to this; C/1961 R1 (Humason), 29P/Schwassmann–Wachmann 1, C/1995 O1 (Hale-Bopp) and the Centaur Chiron (expand), making this a significant discovery, leading to repeat observations of C/2002 VQ94 (LINEAR) 10 April 2007, when the comet was 7.33 AU from the Sun, and emissions of the ions CO+ and N₂+ were again detected, though the neutral molecules CN and C₃ were no longer detectable.

In a paper published on the arXiv database at Cornell University Library on 14 January 2014 and accepted for publication in the journal Icarus, Pavlo Korsun, Philippe Rousselot of the Observatoire des Sciences de l'Univers THETA at the University of Franche-Comté, Irina Kulyk of the Main Astronomical Observatory of National Academy of Sciences of Ukraine and Viktor Afanasiev and Oleksandra Ivanova describe the results of a series of follow-up observations of C/2002 VQ94 (LINEAR) using the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences in March 2008 and March 2009 and the 2.5-m Nordic Optical Telescope  at the Observatory del Roque de los Muchachos in June 2011 and July 2013.

In March 2008 C/2002 VQ94 (LINEAR) was 8.36 AU from the Sun. A cometary halo was still visible, and it was possible to detect the presence of CO+ and N₂+ spectrographically, and to determine the densities of these molecules within the coma (cloud of material around the comet), at 0.0572 grams per cubic meter for N₂+ and 0.00913 grams per cubic meter for CO+. In addition the comet was calculated to be producing dust (particulate solid material released by the sublimation of ice to gas; there is no liquid phase in a vacuum) at a rate of 10-20 kg per second. 

In March 2009 C/2002 VQ94 (LINEAR) was 9.86 AU from the Sun. A cometary halo was still clearly visible, but it was not possible to perform a spectrographic analysis of this. The comet was calculated to be producing dust at a rate of 4-6 kg per second.

In June 2011 C/2002 VQ94 (LINEAR) was 13.40 AU from the Sun. A cometary halo was still faintly visible, though spectrographic analysis of this was not possible. The comet was calculated to be producing dust at a rate of 3-5 kg per second.

In July 2013 C/2002 VQ94 (LINEAR) was 16.84 AU from the Sun. By this point all cometary activity appeared to have ceased.

Korsun et al. also produced a revised size estimate for C/2002 VQ94 (LINEAR), of approximately 48 km in diameter.

120"×120" extractions from the summarized images of VQ94. North, East, sunward direction, and scale bar are indicated. The vertical narrow box across the comet marks the position of the slit in the spectroscopic mode. Korsun et al. (2014).

CO+ and N₂+ are unusual in cometary emissions; they have only previously been detected from three other comets, C/1908 R1 (Morehouse), C/1961 R1 (Humason) and 29P/Schwassnann-Wachmann 1. As a group these four bodies have little in common; C/1908 R1 (Morehouse) was a hyperbolic comet (expand) which reached perihelion at 0.95 AU and had an orbit inclined at 140.2˚ to the plane of the Solar System, C/1961 R1 (Humason) has not been placed in any defined orbit class, it reached perihelion at 2.13 AU and has an orbit inclined at 153.3˚ to the plane of the Solar System and 29P/Schwassnann-Wachmann 1 is a Jupiter Family Comet (expand) with a perihelion of 5.74 AU and an orbit inclined at 9.4˚ to the plane of the Solar System.

The calculated orbit of C/1908 R1 (Morehouse). JPL Small Body Database Browser.

CO+ and N₂+ are likely to be derived from CO and N2 ices, which can only form at very low temperatures; laboratory experiments have suggested these ices can only accumulate at 25 K or less (-148˚C or less), and bodies containing them must have formed in a part of the Solar System where such temperatures occurred. Significantly three of the four comets recorded to have produced CO+ and N₂+ emissions are also members of the six known bodies that have produced detectable molecular emissions at distances of greater than 5 AU from the Sun.

See also…

 Comet C/2013 UQ4 (Catalina) reaches its perihelion.

Comet C/2013 UQ4 (Catalina) will reach its perihelion (the closest point on its orbit to the Sun) on Sunday 6 July 2014. The comet will be at its closet to Earth four days later, slightly before midday on...


 Comet C/2014 E2 (Jacques) reaches perihelion.

Comet C/2014 E2 (Jacques) will reach its perihelion (the closest point on its orbit to the Sun)  on Thursday 3 July 2014, reaching its brightest in the sky (seen from Earth) a later in July, when it should...


 Faye's Comet reaches its perihelion.

Faye's Comet (Comet 4P/Faye) reached it's perihelion (the closest point in its orbit to the Sun) on 29 May 2014, for the first time in seven-and-a-half years. It presents no danger to the Earth, as it never comes within the orbit of Mars, and was not easily visible on this occasion, as the perihelion occurred on the far side of the Sun.

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Comet C/2011 L4 (PANSTARRS) to reach its closest point to Earth this week.

Comet C/2011 L4 (PANSTARRS) will come within 1.1 AU of the Earth (1.1 times as distant as the Sun) on Tuesday 5 March 2013. The comet is visible with binoculars in the Southern Hemisphere, and should become visible in the Northern Hemisphere from 7 March, and possibly become bright enough to be seen with the naked eye. The comet is already closer to the Sun than the Earth, and indeed Venus, but not close to us and traveling at a very high angle to the plane of the Solar System. It will reach its perihelion (closest point to the Sun) on 10 March, when it will potentially be at its brightest (though comets are notoriously hard to predict), and should remain visible for the rest of the Month. It will be easiest to locate on 12-14 March, when it is closest to the Moon, though it might be hard to see at this time due to the Moon's brightness.

The passage of comet C/2011 L4 (PANSTARRS) in February-April 2013. Eagle Eye on the Sky.

Comet C/2011 L4 (PANSTARS) is thought to be a non-periodic comet on its first visit to the inner Solar System, having been disturbed from its previous orbit within the Oort Cloud some time within the last few million years. It is likely that it will revisit the inner Solar System every 110 000 years from now on. It was discovered in June 2011 by the Pan-STARRS (Panoramic Survey Telescope and Rapid Response System) array of telescopes on Haleakala, Hawaii. It will move away from the (Northern Hemisphere) horizon during April, becoming fainter and disappearing towards the North Pole as it moves away from the Sun. It will not be visible from the Southern Hemisphere during this time.

The orbit of comet C/2011 L4 (PANSTARRS). Image created using the JPL Small-Body Database Browser.

See also 99942 Apophis to fly by the Earth, The Earth approaches its perihelion, Possible second meteor shower to coincide with the Geminids, Asteroid 4179 Toutatis/1989 AC to fly past the Earth and The Geminid Meteors.

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