Second Star to the Right …

tinkerbell_eso… and straight on ’til morning. Just follow Tinker Bell. This image from the ESO‘s Very Large Telescope shows a rare merger of three galaxies. The system, which bears a resemblance to Tinker Bell, is composed of two massive spiral galaxies and a third irregular galaxy.

The image is a multi-band composite of infrared data from the  VLT combined with archive images from Hubble. The VLT data allowed astronomers to not only see the two previously known galaxies, but to identify a third, an irregular, massive galaxy that seems to form stars at a frantic rate.

Image Credit: ESO


These are the final images of the asteroid moonlet Dimorphos taken by the DRACO camera about the DART spacecraft as it crashed into Dimorphos. The moonlet is only about 170 m (560 ft) in diameter, making it one of the smallest astronomical objects that has been given a permanent name. Early telemetry suggests that DART hit within 17 m of dead center.


Video Credit: NASA / APL

LMC in IR and Radio

The Large Magellanic Cloud (LMC) is a satellite of the Milky Way containing about 30 billion stars. In this combined radio and near infrared view the LMC’s cool and warm dust are shown in green and blue, respectively, and hydrogen gas in red. The image is composed of data from the European Space Agency Herschel and Planck missions; two retired NASA missions, the Infrared Astronomy Survey and Cosmic Background Explorer; and the ground-based Parkes, ATCA, and Mopra radio telescopes.

Image Credits: ESA / NASA / NASA-JPL / Caltech ; Christopher Clark (STScI) / S. Kim (Sejong University) / T. Wong (UIUC)

The Fornax Dwarf

Fornax_dwarf_galaxyThe Fornax Dwarf Spheroidal is an elliptical dwarf galaxy found in the constellation Fornax. The galaxy is a satellite of the Milky Way and is receding from the us at 53 km/s. It contains six know globular star clusters, an unusually large number for such a small galaxy. Four of them (Fornax 1, 2, 3, and 5) are pictured below.

Image Credits: ESO and ESA

Jupiter is Ready for Its Close Up

However, it’s not too close. It’s over 365 million miles away, but that’s about as close as it ever gets. Next Monday, the giant planet reaches opposition, when the planet and the Sun are on opposite side of the Earth. The planet  rises in the east as the Sun sets in the west.

Jupiter’s opposition occurs every 13 months, but during this opposition, it will also make its closest approach to Earth in the last 70 years. The orbits of the planets are ellipses with the Sun, so planets will pass each other at different distances at opposition. Jupiter’s closest approach to Earth rarely coincides with opposition. This year’s views should be extraordinary. Grab a pair of binoculars or a telescope and take a look.

Image Credit: NASA / ESA / A. Simon (GSFC), and M.H. Wong (UC Berkeley)

Sex and the Immune System

MIT Technology Review has an article about the quest to show that biological sex matters in the immune system. It centers around the work of Sabra Klein, a Professor of Molecular Microbiology and Immunology at the Johns Hopkins Bloomberg School of Public Health. Both the biological and behavioral difference between the sexes are important. For example—

Despite a historical practice of “bikini medicine”—the notion that there are no major differences between the sexes outside the parts that fit under a bikini—we now know that whether you’re looking at your metabolism, heart, or immune system, both biological sex differences and sociocultural gender differences exist. And they both play a role in susceptibility to diseases. For instance, men’s greater propensity to tuberculosis—they are almost twice as likely to get it as women—may be attributed partly to differences in their immune responses and partly to the fact that men are more likely to smoke and to work in mining or construction jobs that expose them to toxic substances, which can impair the lungs’ immune defenses.

How to tease apart the effects of sex and gender? That’s where animal models come in. “Gender is a social construct that we associate with humans, so animals do not have a gender,” says Chyren Hunter, associate director for basic and translational research at the US National Institutes of Health Office of Research on Women’s Health. Seeing the same effect in both animal models and humans is a good starting point for finding out whether an immune response is modulated by sex.
But you can’t find sex differences if you’re only studying one sex. Klein remembers a meeting where a researcher on nematodes, a type of parasitic worm, mentioned that his experiments were done only in male mice, because female mice didn’t get infected. She recalls being flabbergasted that he never thought to study why the nematodes couldn’t infect the females. “Oh my God, you might have a cure for these nematodes that wreak havoc!” she recalls thinking.

BTW, given the politics of many of the likely readers, the article wisely provides this definition—

When referring to people in this article, “male” is used as a shorthand for people with XY chromosomes, a penis, and testicles, and who go through a testosterone-dominated puberty, and “female” is used as a shorthand for people with XX chromosomes and a vulva, and who go through an estrogen-dominated puberty.

Well, at least MIT may have a reasonable working definition for woman.

Read the whole thing.

You Can’t See This From Here

The Cassini spacecraft took this wide-angle view of Saturn on 28 October, 2016, when it was about 1.4 million km from the planet. This point of view is from the far side of the planet showing shadows that can’t be seen from Earth. The spacecraft has spent 13 years exploring Saturn and its moons before being de-orbited into the planet’s atmosphere..

Image Credit: NASA

Overlapping Galaxies

These two galaxies, SDSS J115331 and LEDA 2073461, are more than a billion light-years from Earth. They’re not about to collide. One is farther away from us than the other.

Video Credit: ESA /  NASA / W. Keel
Music Credit: Stellardrone – Billions and Billions
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