Tag: Planet

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Marble by petro c. k.

big blue marble
another turn
for the steelie

by petro c. k.

It shocked people earlier this year when news circulated that scientists calculated that the earth’s inner core is reversing its rotation in relation to the earth’s rotation of the crust. Don’t worry, this is fine. The solid metal core inside the earth spins cushioned by the liquid molten magma layer, with calculations showing that the speed of its rotation is independent of the rotation of the outer core. New research suggests every 35 years or so the inner metal ball slows down, stops, then switches direction. This 70-year cycle may explain corresponding differences to the earth’s magnetic fields and the length of the days.

In the game of marbles, solid metal marbles are called “steelies” and based on the author’s childhood, larger ones are especially prized.

Further reading:

‘Earth’s inner core may be reversing its rotation’, 2023, Science News: https://www.sciencenews.org/article/earth-inner-core-reverse-rotation

‘Multidecadal variation of the Earth’s inner-core rotation’, 2023, Y. Yang & X. Song, Nature Geoscience: https://doi.org/10.1038/s41561-022-01112-z

Author bio:

petro c. k. is a temporal being living on a spinning rock in a vast universe who writes tiny haiku about infinitesimally small moments of time. You can catch up with petro on Twitter here: @petro_ck

Check out other sciku by petro c. k. here: ‘Saturn’s Moons’, ‘Young Star’, and ‘Giggling’.

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Saturn’s Moons by petro c. k.

Saturn’s moons
enough thumbnails
to fill a jar

By petro c. k.

Saturn has the most moons of any planet in the solar system. As of now there are 83 confirmed moons that aren’t part of Saturn’s ring structure, of which 20 are still unnamed.

Saturn’s rings are made up of orbiting objects ranging in size from microscopic to moonlets hundreds of meters across. So far over 150 moonlets have been detected within the rings but the precise number of Saturnian moons cannot be determined since there is no objective boundary between the countless small anonymous objects that form Saturn’s rings and the larger objects that have been named as moons, but the moonlets that have been detected within the ring system are considered a small amount of the total amount actually there.

Current advances in the technology of telescopes as well as observations by unmanned spacecraft have lead to recent discoveries, with 20 new satellites discovered in 2019 alone, allowing Saturn to overtake Jupiter as the planet with the most known moons.

Postscript: In the interval between the writing of this verse and background information, more moons have been found around Jupiter, overtaking Saturn for the most moons:

Further reading:

‘Saturn’s moons: Facts about the weird and wonderful satellites of the ringed planet’, Space.com: https://www.space.com/20812-saturn-moons.html

‘Saturn Moons’, NASA: https://solarsystem.nasa.gov/moons/saturn-moons/overview/

‘Astronomers discover 12 new moons around Jupiter, putting count at record-breaking 92’, CBS News: https://www.cbsnews.com/news/astronomers-12-new-moons-record/

Author bio:

petro c. k. is a temporal being on a habitable rock spinning in space that tries to compress observations of an infinitesimally small section of the universe into haiku. You can catch up with them on Twitter here: @petro_ck

Check out other sciku by petro c. k. here: ‘Young Star’, ‘Marble’, and ‘Giggling’.

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Diamond Rain

Does Neptune ever
feel lonely, with a wall of
diamonds round it’s heart?

Diamonds might be precious but they’re composed of carbon, an element that’s common here on Earth and throughout the universe.

Under the right conditions (pressure and heat) carbon turns into diamonds. Marvin Ross predicted in 1981 that such conditions might be found in the mantels of the Solar System’s ice giants, Neptune and Uranus.

Recent research has supported this, with laser shock experiments on polystyrene performed by Kraus et al. (2017) replicating the conditions approximately 10,000km below the surfaces of Neptune and Uranus. Their experiments created nanodiamonds, supporting evidence that diamond precipitation occurs in the mantels of these planets.

Now further research has strengthened this evidence. The earlier studies used pure hyrdrocarbon systems (polystyrene is C8H8) but the interiors of Neptune and Uranus are more complex than that, consisting mainly of a dense fluid mixture of water (H2O), methane (CH4), and ammonia (NH3).

To understand diamond formation under more complex conditions similar to those found on Neptune and Uranus, Zhiyu et al. (2022) investigated diamond formation using polyethylene terephthalate (PET) plastics (C10H8O4). The researchers found that diamond formation is likely to be enhanced by the presence of oxygen, which in their research accelerated the splitting of the carbon and hydrogen.

Under the conditions found on Neptune and Uranus it’s likely that much larger diamonds would be formed, potentially millions of carats in weight. Over millennia these vast diamonds are predicted to sink slowly through the icy layers of the mantel before melting near the cores, creating an ever changing layer of diamonds around the cores of the planets.

The latest research may also explain another peculiarity about Neptune and Uranus: their unusual magnetic fields. Under the conditions that form diamonds in the mantel, the researchers also found evidence that superionic water might be created. Superionic water conducts electric current and is likely to impact the planets’ magnetic fields.

In addition to learning more about the Universe, there are practical implications for us on Earth resulting from the research too. Nanodiamonds have a range of important uses, including in medical sensors, non-invasive surgery, sustainable manufacturing, and quantum electronics. This latest research points the way towards a new way of fabricating nanodiamonds for such uses.

Further reading:

Ross, M. (1981) The ice layer in Uranus and Neptune—diamonds in the sky? https://doi.org/10.1038%2F292435a0

Kraus, D. et al. (2017) Formation of diamonds in laser-compressed hydrocarbons at planetary interior conditions https://doi.org/10.1038/s41550-017-0219-9

Zhiyu, H.E. et al. (2022) Diamond formation kinetics in shock-compressed C─H─O samples recorded by small-angle x-ray scattering and x-ray diffraction https://doi.org/10.1126/sciadv.abo0617

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The Dimming Forebear

Gaia. Rooting out
planetary impostures.
K’s false positives.

The Kepler Space Telescope was designed to discover earth-sized planets orbiting around other stars within our region of the Milky Way. Named after German astronomer and mathematician, Johannes Kepler, it was launched in 2009 and retired on the 15th November 2018, the 388th anniversary of the death of its namesake in 1630.

During its lifetime the Kepler Space Telescope discovered 2,662 planets, something it achieved by observing 530,506 stars and looking for drops in their intensity that could indicate a planet passing in front of them. Among these planets were some that were the correct distance from their star and had the right size and atmospheric pressure to support liquid water at the planet’s surface. Other planets discovered orbited two stars instead of one, and ‘hot Jupiters’ – gas giants similar to Jupiter but orbiting in close proximity to their star.

Yet telescopes continue to advance technologically. The Kepler Space Telescope used a photometer to observe the stars in its field of view. The Gaia Space Observatory, launched in 2013, uses a photometer along with an astrometry instrument and a radial-vector spectrometer.

Now research by Niraula et al. (2022) suggests that three or even four of the planets identified by the Kepler Space Telescope aren’t planets at all but are in fact stars. The team was reviewing the planetary data produced by the Kepler Space Telescope and realised that with updated measurements from the Gaia Space Observatory the ‘planets’ Kepler-854b, Kepler-840b, and Kepler-699b were far too large to be planets – each of them two to four times the size of Jupiter. The fourth ‘planet’, Kepler-747b, is 1.8 times the size of Jupiter, at the very top end of observed planets, but its far distance from its star suggests that its more likely to be a star itself than a planet.

Four out of over two and a half thousand discovered planets isn’t a large amount and certainly doesn’t take anything away from the incredible job that the Kepler Space Telescope did during its lifetime. Yet the new findings are hugely important for our knowledge and understanding of planets – by correcting this error the planet dataset is more accurate for those who are studying the population of planets as a whole.

Original research: http://dx.doi.org/10.3847/1538-3881/ac4f64

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2M0437b

An ancient baby
in a stellar nursery.
Hot off the star press.

One of the youngest planets ever discovered has been recorded by a team of researchers working with the Subaru and Keck-2 telescopes on the dormant volcano Mauna Kea on the island of Hawai’i. The planet, 2M0437b, was first spotted in 2018 and has taken 3 years of observations to confirm.

Planet 2M0437b. The image was taken with the Subaru Telescope on Maunakea. Credit: Subaru Telescope and Gaidos, et al. (2021)

2M0437b is found, along with its parent star (2M0437), in a stellar ‘nursery’ called the Taurus Cloud and was formed several million years ago, around the same time as when the island it was observed from emerged above the ocean. In fact, the planet is so young it’s still hot from its formation, approximately the temperature of lava: 1400-1500K. The planet is a few times larger than Jupiter and has an orbit around its star that’s around 100 times as far as the distance between Earth and the Sun.

Subaru Telescope and Keck Observatory on Maunakea. Credit: University of Hawaii Institute for Astronomy

The young planet can help further build our understanding of how planets form, and challenges some current explanations. As Gaidos et al. (2021) say “the discovery of a super-Jupiter around a very young, very low mass star challenges models of planet formation by either core accretion (which requires time) or disc instability (which requires mass).” Future observations with space telescopes such as the Hubble will help to provide more information about the infant planet and further build our knowledge of the universe.

Original research: https://arxiv.org/abs/2110.08655

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Iron rain

Ferrous droplets fall
on the nightside of poor locked
WASP. A fishy place.

In the constellation Pisces, 640 light years away from Earth, there is a planet that orbits so closely to its star that it rains iron.

A team of around 100 researchers (Ehrenreich et al, 2020) used the European Southern Observatory’s Very Large Telescope in Chile to observe the vast exoplanet WASP-76b and found that temperatures reach above 2400 degrees Celsius, hot enough for iron to vaporise.

WASP-76b is tidally locked, meaning that its spin and rotation around its star coincide, with one side of the planet always in darkness and one side always facing the star – in the same way that our moon always presents the same side to the Earth. Strong winds are created as a result of a temperature difference of around 900 degrees Celsius between the sun-facing dayside and the perpetually dark nightside. Iron is vapourised on the dayside and these winds carry the iron vapour to the cooler side of the planet where it condenses and rains down.

A note about “A fishy place” – this is a reference to WASP-76b’s location in the constellation of Pisces, which in astrology is the sign of the fish.

Original research: https://doi.org/10.1038/s41586-020-2107-1

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Patches on Venus

Patches on Venus:

Atmosphere harbouring the

conditions for life?

 

In the hunt for extra-terrestrial life, Venus is rarely considered due to the high surface temperatures (~465 °C) and the intense atmospheric pressure (92 times that on Earth). Yet a new study by Limaye et al (2018) suggests that life off the surface of the planet may be possible since the lower cloud layer harbours conditions suitable for microbial life: water, solutes, ~60 °C and an atmospheric pressure roughly equivalent to Earth.

What’s more, observations of Venus have revealed dark patches in the atmosphere that change shape, size and position over time. These are made up of particles roughly the same size as common Earth bacteria and also absorb light of at a similar spectrum. The changes in patch patterns could therefore be the equivalent of algae blooms.

Venus is thought to have once had water on its surface, potentially for as long as 2 billion years providing enough time for life to evolve. As the surface water evaporated the microorganisms could have been transported to the clouds, in similar ways to how bacteria have been found in the atmosphere of Earth (although on Earth aerial microbes do not appear to remain aloft indefinitely). Life on the second planet from the sun therefore remains a possibility and only further observations and potentially even atmospheric sampling will reveal whether the changing dark patches are indeed patterns of microbial life.

Original research: https://doi.org/10.1089/ast.2017.1783