Earth Has An Asteroid Buddy


In 2016 planetary astronomers at the University of Arizona Lunar and Planetary Laboratory discovered a small ( 100 meter ) object moving with Earth around the Sun. Dubbed 2016 OR3, initial science speculation wondered if it might be a piece of space junk, perhaps a rogue rocket booster caught in wobbly orbit occasionally intersecting Earth orbit.

Last week at the annual Division For Planetary Sciences  meeting in Provo, Utah Vishnu Reddy from University of Arizona laid speculation to rest, identifying 2016 OR3 as an asteroid, stating in part –

“2016 HO3 is a small near-Earth object (NEO) measuring no more than 100 meters (330 feet) across that, while orbiting the sun, also appears to circle around the Earth as a quasi-satellite. Only five quasi-satellites have been discovered so far, but 2016 HO3 is the most stable of them. The provenance of this object is unknown. On timescales of a few centuries, 2016 HO3 remains within 38 to 100 lunar-distances from us.”

“One way to visualize HO3’s orbit is by picturing a hula hoop dancer — the sun in this analogy — twirling two hoops around the hips at the same time, ever so slightly out of sync. While it orbits the sun, the object makes yearly loops around the Earth.

As a result, the object appears to orbit the Earth, but it is not gravitationally bound to our planet.”

2016 HO3 is seen at the top left corner of this animation made of ten 2mn long exposures in I band using MODS1 on the left side of LBT – The telescope is tracking the moving asteroid, so background stars (and even a couple of galaxies) are trailed. Image via LBTO.

Asteroid 2016 OR3 is hardly a harbinger of doom – orbiting politely at 38 – 100 lunar distance from Earth, it is a cosmic companion which now bears official designation of quasi-satellite. NASA Jet Propulsion Laboratory said –

The asteroid’s orbit also undergoes a slow, back-and-forth twist over multiple decades. “The asteroid’s loops around Earth drift a little ahead or behind from year to year, but when they drift too far forward or backward, Earth’s gravity is just strong enough to reverse the drift and hold onto the asteroid so that it never wanders farther away than about 100 times the distance of the moon,” said Chodas. “The same effect also prevents the asteroid from approaching much closer than about 38 times the distance of the moon. In effect, this small asteroid is caught in a little dance with Earth.”

https://www.jpl.nasa.gov/news/news.php?feature=6537

“Caught in a little dance with Earth” makes me smile. Not for knowing Earth has an asteroid buddy, but for affirmation everything in our universe is caught in a little dance.

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Skyglow


The term skyglow evokes poetic images – sunset petticoats of periwinkle clouds caught in flirtatious embrace with plump pomegranate horizons, gossamer tendrils of moonlight skipping playful stones across still water, calming arias of ethereal pre-dawn planetary conjunctions – all may glow, but none define skyglow.

Skyglow is light pollution. Artificial, unshielded, unnatural light directed upward into the atmosphere. Driving at night we’ve all seen a distant glowing dome over towns and cities, that is skyglow – the reason I strain to hear childhood stars sing.

In 1928 naturalist and writer Henry Beston published The Outermost House. In it he wrote –

Our fantastic civilization has fallen out of touch with many aspects of nature, and with none more completely than with night. Primitive folk, gathered at a cave mouth round a fire, do not fear night; they fear, rather, the energies and creatures to whom night gives power; we of the age of the machines, having delivered ourselves of nocturnal enemies, now have a dislike of night itself. With lights and ever more lights, we drive the holiness and beauty of night back to the forests and the sea; the little villages, the crossroads. Are modern folk, perhaps, afraid of night? Do they fear that vast serenity, the mystery of infinite space, the austerity of stars? Having made themselves at home in a civilization obsessed with power, which explains its whole world in terms of energy, do they fear at night for their dull acquiescence and the pattern of their beliefs? Be the answer what it will, today’s civilization is full of people who have not the slightest notion of the character or the poetry of night, who have never even seen night. Yet to live thus, to know only artificial night, is as absurd as to know only artificial day.
― Henry Beston, The Outermost House, 1928

Entirely light polluted Shenandoah National Park, Virginia

Entirely light polluted Shenandoah National Park, Virginia – “In Shenandoah National Park, only the occasional passing clouds block enough light from the surrounding cities to offer visitors a decent view of the heavens. With an estimated light pollution growth at 6 percent a year, National Parks, along with all of the developed world, may lose their dark skies by the end of the 21st Century.” – https://skyglowproject.com/#dark-sky-movement

Light Pollution Visualization.jpg

In 1958 Flagstaff, Arizona became the first city to pass light pollution laws. City ordinances prohibited the use of commercial search lights within city limits, violation of said ordinance was punishable by up to 90 days in jail. In 2001 the International Dark Sky Association named Flagstaff the first international dark sky community in recognition of pioneering efforts to maintain dark skies.A well deserved nod born in 1958, schooled through 1973 when Flagstaff’s county of Coconino passed sweeping lighting code regulations, and educated by 1981 when all illuminated billboards were banned.

Flagstaff is world's only city of 100,000+ residents to feature readily-available dark skies. 

Flagstaff is world’s only city of 100,000+ residents to feature readily-available dark skies.

With the estimated light pollution growth of 6% a year, all of developed world may lose its dark skies by the end of the 21st century.

“Skyglow” is also a project by timelapse photographers Harun Mehmedinovic and Gavin Hefferman to raise awareness of light pollution. Spend a video moment with Gavin and Harum, it will forever change how you gaze at night skies. –

“The age of dark skies, with us from the very beginning of humanity, has come to an abrupt end.” – https://skyglowproject.com/#music

 

 

Have You Seen The Milky Way?


Born under starry skies, rural seclusion wrapped childhood in the Milky Way. Constant, permanent, watchful – I left for city lights without saying goodbye. We still see each other every few years, picking up where we left off like old friends do. When time comes to part I wave goodbye, mindful of cosmic wonders that shaped my life. Pondering the fact 80% of people alive today have never seen the Milky Way.

http://ngm.nationalgeographic.com/2008/11/light-pollution/klinkenborg-text

 

Space Videos


My space geek swooned when idle YouTube navigation delivered the Amazing Space channel – one stop catalogue of cosmic magnificence. Regardless of mood or inclination, be it timelapse, Hubble, SDO, NASA, ESA, live feeds, JUNO orbiting Jupiter, ISS or 30 minutes of high definition solar artistry dubbed Thermonuclear Art – Amazing Space is the place.

http://https://www.youtube.com/user/ouramazingspace/featured

 

Five Bright Planets


Between January 20 – February 20, 2016 Mercury, Venus, Saturn, Mars and Jupiter will be visible to the naked eye – five bright planets in a row, for the first time since December 2004.

Beginning around January 20 - through mid-February - you can see five bright planets at once in the predawn sky.

View larger. | Beginning around January 20 – through mid-February – you can see five bright planets at once in the predawn sky.

Sleep is precious, so too is an opportunity to gaze at over half our planets in the theatre of pre-dawn’s quiet contemplation. Jupiter is first to rise in the early evening, followed by Mars after midnight, then Saturn, Venus and Mercury just before dawn. Those living in North America can click on the link below for precise rise and set time of moon, sun and planets depending on your location.

http://www.almanac.com/astronomy

The rest of you can use the next link. It requires a little patience and navigation to obtain longitude and latitude – but hey, you’ll learn your city’s coordinates along the way.

http://aa.usno.navy.mil/data/docs/mrst.php

http://earthsky.org/science-wire/when-will-all-five-visible-planets-appear-simultaneously?utm_source=EarthSky+News&utm_campaign=75402ed4f6-EarthSky_News&utm_medium=email&utm_term=0_c643945d79-75402ed4f6-393970565