Month: December 2021

Enlarge / Rocket Lab calls this the "Hungry Hippo" fairing on its Neutron rocket. (credit: Rocket Lab)

Welcome to Edition 4.25 of the Rocket Report! After the Thanksgiving holiday, we are now in the homestretch of 2021, with less than a month to go in the year. And it will be a consequential month, with a Soyuz crew launch on deck, NASA's IXPE science mission, and—of course—the James Webb Space Telescope on December 22. Buckle up!

As always, we welcome reader submissions, and if you don't want to miss an issue, please subscribe using the box below (the form will not appear on AMP-enabled versions of the site). Each report will include information on small-, medium-, and heavy-lift rockets as well as a quick look ahead at the next three launches on the calendar.

Astra successfully reaches orbit. Astra never sought to build the best rocket, the biggest rocket, or the safest rocket. The California-based space company simply wanted to build a rocket that was just good enough—and to do it fast. On November 20, Astra proved the value of this philosophy by successfully launching a stripped-down rocket for the first time. The mission hefted a small test payload for the US Space Force into an orbit 500 km above the planet, Ars reports.

Enlarge / The TESS planet-finding observatory. (credit: NASA)

For centuries, scientists only had a limited number of examples to look at when it came to understanding the formation of planets. As we've discovered ever-increasing numbers of worlds, however, we've found many that look like nothing what we have in our Solar System: hot gas giants, super-Earths, mini-Neptunes, and more. So, it can be a relief to find something that looks like a familiar planet, since it indicates the processes that formed the Solar System may not be unusual.

A new discovery definitely falls into that category, as researchers have announced finding what appears to be an extremely iron-rich planet that, at least composition-wise, is very similar to Mercury. The difference is that it's nearly on top of its star and is probably hot enough that any iron on the surface could potentially be molten.

A very short year

The new planet was found orbiting a red dwarf star named GJ 367 that's about 30 light years from Earth. Red dwarfs are small, dim stars, which makes identifying planets around them easier. A planet that orbits between a red dwarf and Earth will block out proportionally more of the star's light. And, because the star is low mass, a planet's gravity will cause it to shift further when it orbits, creating larger Doppler shifts in the light originating from the star.

Enlarge / Detail of Michelangelo's unfinished painting The Virgin and Child with Saint John and Angels (tempera on wood, ca. 1497), aka The Manchester Madonna. The outlines of two angelic figures on left are rendered in green earth tempera underpaint. (credit: The National Gallery London/Public domain)

Tempera is a painting medium that has been used to decorate everything from early Egyptian sarcophagi to India's rock-cut temples. The medium was particularly popular with medieval and early Renaissance artists until it was eventually supplanted by oil-based paints. But while there has been a great deal of research on the chemistry of oil paints, tempera has been largely neglected in the scientific literature, according to researchers at the Sorbonne University in France.

To remedy that, the Sorbonne scientists recreated recipes for tempera written down by a medieval Tuscan painter, the better to analyze the flow properties and molecular organization of the paints, according to a recent paper published in the journal Angewandte Chemie. The aim is to gain a more precise understanding of the underlying chemistry in order to aid in ongoing conservation efforts on tempera-based artworks from the Middle Ages in particular.

Tempera in this context refers to a fast-drying paint in which colored pigments are mixed with a water-soluble binder—traditionally egg yolk, often augmented with an agent such as a few drops of vinegar to prevent cracking once the tempera has dried. The powdered pigment and distilled water would be mixed with binder directly onto the palette, or in a bowl. Liquid myrrh was sometimes added to offset the tempera's rather pungent odor. Artists had to keep adding water as they worked because the medium dried so quickly, and in those days, tempera could not be stored because the yolk would begin to cure, thickening the paint. While tempera fell out of favor after 1500, it is periodically rediscovered. For instance, 20th-century artists like Jacob Lawrence and Andrew Wyeth used tempera in their work.