Category Archives: Science

Solar activity follows an approximately 11 year cycle, the minimal point of which occurred last December. Solar Cycle 25 has now begun. To wit:

…[the] quiet Sun, at minimum activity, appears on the right of this split hemispherical view. In contrast, the left side shows the active Sun at the recognised maximum of Solar Cycle 24, captured in April 2014. The extreme ultraviolet images from the orbiting Solar Dynamics Observatory highlight coronal loops and active regions in the light of highly ionised iron atoms. Driving the space weather around our fair planet, Solar Cycle 24 was a relatively calm one and predictions are that cycle 25 will be calm too. The cycle 25 activity maximum is expected in July 2025. Solar Cycle 1, the first solar cycle determined from early records of sunspot data, is considered to begin with a minimum in February 1755.

(Image: NASA, SDO)

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Behold: asteroid Bennu. Nobody knows why this carbonaceous behemoth (which could impact the Earth sometime in the next 180 years) ejects gravel into space. But that’s what it does. To wit:

The discovery, occurring during several episodes by NASA‘s visiting OSIRIS-REx spacecraft, was unexpected. Leading ejection hypotheses include impacts by Sun-orbiting meteoroids, sudden thermal fractures of internal structures, and the sudden release of a water vapour jet. The featured two-image composite shows an ejection event that occurred in early 2019, with sun-reflecting ejecta seen on the right. Data and simulations show that large gravel typically falls right back to the rotating 500-metre asteroid, while smaller rocks skip around the surface, and the smallest rocks completely escape the low gravity of the Earth approaching, diamond-shaped asteroid. Jets and surface ejection events were thought to be predominantly the domain of comets, responsible for their tails, comas, and later meteor showers on Earth. Robotic OSIRIS-REx arrived at 101955 Bennu in late 2018, and is planned to touchdown to collect a surface sample in October 2020. If all goes well, this sample will then be returned to Earth for a detailed analysis during 2023. Bennu was chosen as the destination for OSIRIS-REx in part because its surface shows potential to reveal organic compounds from the early days of our Solar System, compounds that could have been the building blocks for life on Earth.

(Image: NASA‘s GSFC, U. Arizona, OSIRIS-REx Lockheed Martin)

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But have you ever heard the wolf cry to a blue one?

Never mind.

Moonrise can be a stunning sight. But there’s nothing quite like a rising Corn Moon. To wit:

A rising Full Corn Moon was captured early this month in time-lapse with a telephoto lens from nearly 30 kilometres away — making Earth’s ascending half-degree companion appear unusually impressive. The image was captured from Portugal, although much of the foreground — including lights from the village of Puebla de Guzmán — is in Spain. A Full Corn Moon is the name attributed to a full moon at this time of year by cultures of some northern indigenous peoples of the Americas, as it coincides with the ripening of corn. Note that the Moon does not appear larger when it is nearer the horizon — its seemingly larger size there is only an illusion. The next full moon — occurring at the beginning of next month — will be known as the Full Harvest Moon as it occurs nearest in time to the northern autumnal equinox and the northern field harvests.

(Image: Zarcos Palma)

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Behold: M2-9, aka, the Twin-Jet or Wings Of A Butterfly nebula – the last great work of a cosmic luminary To wit:

…stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured here, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes. The expended gas frequently forms an impressive display called a planetary nebula that fades gradually over thousands of years. M2-9, a butterfly planetary nebula 2100 light-years away shown in representative colours, has wings that tell a strange but incomplete tale. In the center, two stars orbit inside a gaseous disk 10 times the orbit of Pluto. The expelled envelope of the dying star breaks out from the disk creating the bipolar appearance. Much remains unknown about the physical processes that cause and shape planetary nebulae.

(Image: Hubble Legacy Archive, NASA, ESA – Processing: Judy Schmidt)

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Mars reappears from behind the Moon last Sunday. To wit:

Of course to reappear it had to disappear in the first place. It did that over an hour earlier when the sunlit southern edge of the waning gibbous Moon passed in front of the Red Planet as seen from Maceio, Brazil. The lunar occultation came as the Moon was near apogee, about 400,000 kilometers away. Mars was almost 180 times more distant. It was the fourth lunar occultation of Mars visible from planet Earth in 2020. Visible from some southern latitudes, the fifth lunar occultation of Mars in 2020 will take place on October 3 when the Moon and Mars are both nearly opposite the Sun in planet Earth’s sky.

Remember last month when Saturn did this? 

(Image: David Duarte and Romualdo Caldas)

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Behold: an especially clear and pleasing image of the Pleiades, perhaps the most famous star cluster in the sky. To wit:

 …the bright stars of the Pleiades can be seen without binoculars from even the depths of a light-polluted city. With a long exposure from a dark location, though, the dust cloud surrounding the Pleiades star cluster becomes very evident. The featured exposure covers a sky area several times the size of the full moon. Also known as the Seven Sisters and M45, the Pleiades lies about 400 light years away toward the constellation of the Bull (Taurus). A common legend with a modern twist is that one of the brighter stars faded since the cluster was named, leaving only six of the sister stars visible to the unaided eye. The actual number of Pleiades stars visible, however, may be more or less than seven, depending on the darkness of the surrounding sky and the clarity of the observer’s eyesight.

(Image: Raul Villaverde Fraile)

Another view?

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Behold: Messier 1 – the inextricable mess left over when a star explodes. To wit:

The Crab Nebula – the result of a supernova seen in 1054 AD – is filled with mysterious filaments. The filaments are not only tremendously complex, but appear to have less mass than expelled in the original supernova and a higher speed than expected from a free explosion. The featured image, taken by the Hubble Space Telescope, is presented in three colours chosen for scientific interest. The Crab Nebula spans about 10 light-years. In the nebula‘s very centre lies a pulsar: a neutron star as massive as the Sun but with only the size of a small town. The Crab Pulsar rotates about 30 times each second.

(Image: NASA, ESA, Hubble, J. Hester, A. Loll (ASU)

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It’s diffuse. And gaseous.

Scarlet for yeh.

Behold: M31, aka NGC 244, aka Andromeda  the closest large spiral galaxy to our own Milky Way. But not as it’s normally seen. To wit:

Some 2.5 million light-years distant it shines in Earth’s night sky as a small, faint, elongated cloud just visible to the unaided eye. Invisible to the eye though, its enormous halo of hot ionised gas is represented in purplish hues for this digital illustration of our neighbouring galaxy above rocky terrain. Mapped by Hubble Space Telescope observations of the absorption of ultraviolet light against distant quasars, the extent and make-up of Andromeda’s gaseous halo has been recently determined by the AMIGA project. A reservoir of material for future star formation, Andromeda’s halo of diffuse plasma was measured to extend around 1.3 million light-years or more from the galaxy. That’s about half way to the Milky Way, likely putting it in contact with the diffuse gaseous halo of our own galaxy.

(Digital Illustration: NASA, ESA, J. DePasquale and E. Wheatley (STScI) and Z. Levay)

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One, right?

Wrong. To wit:

.. take a closer look at the object on the upper right. That seeming-star is actually the planet Jupiter, and your closer look might reveal that it is not alone – it is surrounded by some of its largest moons. From left to right these Galilean Moons are Io, Ganymende, Europa and Callisto. These moons orbit the Jovian world just like the planets of our Solar System orbit the Sun, in a line when seen from the side. The featured single shot was captured from Cancun, Mexico last week as Luna, in its orbit around the Earth, glided past the distant planet. Even better views of Jupiter are currently being captured by NASA‘s Juno spacecraft, now in a looping orbit around the Solar System’s largest planet. Earth’s Moon will continue to pass nearly in front of both Jupiter and Saturn once a month (moon-th) as the two giant planets approach their own great conjunction in December.

(Image: Robert Fedez)

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Behold: Messier 42, the Orion Nebula, or rather a visualisation of it based on astronomical data and movie rendering techniques. To wit:

Up close and personal with a famous stellar nursery normally seen from 1,500 light-years away, the digitally modeled frame transitions from a visible light representation based on Hubble data on the left to infrared data from the Spitzer Space Telescope on the right. The perspective at the center looks along a valley over a light-year wide, in the wall of the region’s giant molecular cloud. Orion’s valley ends in a cavity carved by the energetic winds and radiation of the massive central stars of the Trapezium star cluster. The single frame (top) is part of a multiwavelength, three-dimensional video that lets the viewer experience an immersive, three minute flight through the Great Nebula of Orion.

Any excuse…

(Visualization: NASA, ESA, F. Summers, G. Bacon, Z. Levay, J. DePasquale, L. Frattare, M. Robberto, M. Gennaro (STScI) and R. Hurt (Caltech/IPAC)

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