Space

Just before the flyby of Pluto by New Horizons I wrote a speculative fun article about whether it could spot moonlets of Pluto’s moons. Can Moons Have Moons? Or Rings? Theoretically it seems possible that moonlets just possibly might be dynamically stable, there as with many of the moons of our solar system such as the more distant moons in the Saturn system.

Does this discovery of 'The Goblin make 'Planet 9' more likely? Yes I’d say so. It’s looking really strange. I’m beginning to be won around to the idea :). There is plenty of space for planets to exist beyond Neptune. No known big gas giants to get in their way. And - objects get far far fainter the further they are from the sun. It was hard to find, even though it was only 80 au from the Sun - at it's furhest it would be 2300 au away. They spotted it first in 2015 and it's taken since then to figure out its orbit.

Dear Mr Musk, you should hire me to fly Yusaku Maezawa to the Moon and back.  Especially if you want to connect to the past and future history of space flight.  I am a fully qualified scientist with a MS in Physics and a thesis in Astronomy meeting all the basic NASA requirements for an astronaut candidate.  More importantly there are historical reasons, of place and person, that would make you want to hire me as your chauffeur to the stars.

You could hire and probably have hired veteran NASA astronauts and some are training for Crewed Dragon… but not for the BFS.  

Planet dwellers like us naturally look first to other moons and planets for colonization. Yet, asteroids have enough resources to build space habs for trillions, with the same living space per person as for Earth.

The idea is to use the materials from the asteroids and NEOs to make new habitats. This gives far more living space than the amount you get if you hollow asteroids out, and live inside them.

The Moon and Mars are our only choices for surface colonization in the near future. Neither is a second Earth; both have many issues at present, especially, the almost total lack of atmosphere. Technically, Mars does have an atmosphere, true, enough for winds and dust storms, but it is so thin it would count as a laboratory vacuum on Earth.

People often ask, "How close are we to sending humans to Mars" and it's not surprising given the optimistic presentations by Elon Musk and others. However, Mars is just too far away to send humans at this stage.

Consider the statistical challenges around Dysonian SETI. The standard approach (for searches within the Milky Way) is to find stars that are "outliers", e.g. those that are significantly dimmer than their spectrophotometric characteristics and parallax would suggest. Statistical interpretation of the outliers of a single metric's distribution is not straightforward, however.

The normal/gaussian distribution is not normally found in nature. Real-world distributions are often skewed and long-tailed. Outliers (or "black swans") are to be expected.

Some exoplanets with masses two to four times the size of Earth can be explained by large amounts of water - and they may be more common than previously thought, say researchers.

The 1992 discovery of exoplanets orbiting other stars has sparked interest in understanding the composition of these planets to determine, among other goals, whether they are suitable for the development of life. Now a new evaluation of data from the exoplanet-hunting Kepler Space Telescope and the Gaia mission indicates that many of the known planets may contain as much as 50% water. This is much more than the Earth's 0.02% (by weight) water content.

About 1 billion years after the Big Bang, the gas in deep space was highly opaque to ultraviolet light and its transparency varied widely from place to place, obscuring much of the light emitted by distant galaxies. This opaque quality contains tantalizing mysteries about the universe.

That's because now the gas between galaxies is almost totally transparent thanks to being kept ionized-- electrons detached from their atoms--by an energetic bath of ultraviolet radiation.
I am very happy to host here today an article by my INFN colleague Alessandro de Angelis, a well-known and authoritative italian astrophysicist. Alessandro has recently published a beautiful new book on this subject, which I invite you to have a look at (see link at the bottom of the article) - T.Dorigo .
You may have trouble finding a hotspot in that store you are visiting, but there is one place they are persistent: inside neutron stars. A new study shows that instabilities can create intense magnetic hot spots that survive for millions of years, even after the star's overall magnetic field has decayed significantly. 

When a massive star consumes its nuclear fuel and collapses under its own gravity in a supernova explosion, it can result in a neutron star. These very dense objects have a radius of about 10 kilometers and yet are 1.5 times more massive than the Sun. They have very strong magnetic fields and are rapid rotators, with some neutron stars spinning more than 100 times per second round their axis.