Science & Technology
The stainless steel cylinder appeared to rupture near its top after filling with super-cold liquid nitrogen overnight at SpaceX's launch site at Boca Chica, Texas. Elon Musk, SpaceX's founder and CEO, tweeted early Friday that the accident may have been the result of a "test configuration mistake."
The Starship the upper stage of of SpaceX's next-generation launch and space transportation system. Coupled with a massive booster named the Super Heavy, the Starship could haul more than 100 metric tons, or 220,000 pounds, of cargo to low Earth orbit, according to SpaceX.
The fully reusable Super Heavy and Starship vehicles, which will also be able to carry people, will eventually replace the partially reusable Falcon rocket family, SpaceX says.
But testing of Starship prototypes in South Texas has not gone as quickly as Musk hoped. Last September, Musk said he wanted the Starship to reach orbit within six months. That timeframe passed last week, and no full-size Starship test craft has flown yet.

This artist's animation illustrates a massive asteroid belt in orbit around a star the same age and size as our Sun.
The first asteroid that's expected to fly past Earth this weekend is known as 2015 FC35. As indicated in CNEOS' database, this asteroid measures about 820 feet wide. This means it is significantly bigger than the towers of the Golden Gate Bridge in California.
2015 FC35 is expected to approach Earth on April 4 at 5:04 am EDT with an average speed of almost 31,000 miles per hour. During this time, the asteroid will fly past Earth from 0.02679 astronomical units or about 2.5 million miles away.
2015 FC35's visit will then be followed by the arrival of the asteroid 2020 FL6. According to CNEOS, this space rock has an estimated diameter of about 177 feet. It is currently traveling across the Solar System at a speed of almost 27,000 miles per hour.
CNEOS noted that 2020 FL6 would fly past Earth on April 4 at 9:20 am EDT from a distance of 0.01294 astronomical units or roughly 1.2 million miles away.
Until recently, the story of our origins was thought to be settled: Homo sapiens evolved in eastern Africa about 150,000 years ago, became capable of modern behaviour some 60,000 years ago and then swept out of Africa to colonise the world, completely replacing any archaic humans they encountered. But new fossils, tools and analyses of ancient and modern genomes are tearing apart that neat tale. The Jebel Irhoud skull has turned out to be a key to a new, slowly emerging paradigm. With the dust yet fully to settle, the question now is how many, if any, of our old assumptions still hold.
Graham Lawton, "Human evolution: The astounding new story of the origin of our species" at New Scientist
We performed follow-up measurements of this object while it was still on the PCCP webpage.
Stacking of 14 unfiltered exposures, 60 seconds each, obtained remotely on 2020, March 31.5 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a diffuse coma about 1 arcmin in diameter and a tail 20" long in PA 115.
Our confirmation image (click on it for a bigger version)
Today, geomagnetic effects on Earth's biology, and life on the planet overall, is the subject of many fields of investigation. In this episode, we present intriguing evidence that the Sun's electromagnetic activity may influence our bodies and minds in surprising and dramatic ways.
The simplistic portrayals of cells taught in high school biology classes of the 1970s (let us say) stressed general functions, not detailed structures. These included terms like active transport, metabolism, reproduction, and the like, described in broad terms with simple diagrams. Ions go in; waste products go out. No wonder students were bored. Memorize; repeat on test. What if they had been shown the images at the nanometer scale now available to us through advanced imaging technologies like cryo-EM microscopy? They would be texting the images to friends with "Wow!" emojis. Some might have been inspired to become molecular biologists.
Scientists have learned much in the last fifty years about the channels that enable active transport. They have learned that multiple channels exist that control specific molecules. Some aquaporin channels let water in or out. Some voltage-gated channels control the flow of electrically charged molecules, like ions of potassium, sodium, and chloride. Some mechanosensitive channels respond to touch. They have also subdivided these channels into families with similar functions that differ in particular applications, and noted that some channels are so specific, they can distinguish between molecules that differ only minutely in size.
In recent decades, the nature of selectivity filters has been elucidated at the atomic level. Often it is the specific placement of amino acids in the filter that validates and regulates the passage of molecules. Other exciting discoveries explore the nature of conformational changes (i.e., moving parts) in the proteins surrounding the channel pores. Some of these conformational changes mimic the action of slots in a vending machine that will accept dimes but not pennies.
I performed follow-up measurements of this object while it was still on the PCCP webpage. Stacking of 15 unfiltered exposures, 120-sec each, obtained remotely, from Telescope Live (El Sauce, Chile) on 2020, March 25.3, through 0.6-m f/6.5 astrograph + CCD, shows that this object appears slightly diffuse compared to the nearby field stars of similar brightness.
My confirmation image (click on it for a bigger version)
Aims: Studies have indicated that chloroquine (CQ) shows antagonism against COVID-19 in vitro. However, evidence regarding its effects in patients is limited. This study aims to evaluate the efficacy of hydroxychloroquine (HCQ) in the treatment of patients with COVID-19.
Main methods: From February 4 to February 28, 2020, 62 patients suffering from COVID-19 were diagnosed and admitted to Renmin Hospital of Wuhan University. All participants were randomized in a parallel-group trial, 31 patients were assigned to receive an additional 5-day HCQ (400 mg/d) treatment, Time to clinical recovery (TTCR), clinical characteristics, and radiological results were assessed at baseline and 5 days after treatment to evaluate the effect of HCQ.
Key findings: For the 62 COVID-19 patients, 46.8% (29 of 62) were male and 53.2% (33 of 62) were female, the mean age was 44.7 (15.3) years. No difference in the age and sex distribution between the control group and the HCQ group. But for TTCR, the body temperature recovery time and the cough remission time were significantly shortened in the HCQ treatment group. Besides, a larger proportion of patients with improved pneumonia in the HCQ treatment group (80.6%, 25 of 32) compared with the control group (54.8%, 17 of 32). Notably, all 4 patients progressed to severe illness that occurred in the control group. However, there were 2 patients with mild adverse reactions in the HCQ treatment group. Significance: Among patients with COVID-19, the use of HCQ could significantly shorten TTCR and promote the absorption of pneumonia.

A device to capture carbon dioxide from the air and convert it to useful organic products. On left is the chamber containing the nanowire/bacteria hybrid that reduces CO2 to form acetate. On the right is the chamber where oxygen is produced.
For the past eight years, the researchers have been working on a hybrid system combining bacteria and nanowires that can capture the energy of sunlight to convert carbon dioxide and water into building blocks for organic molecules. Nanowires are thin silicon wires about one-hundredth the width of a human hair, used as electronic components, and also as sensors and solar cells.
Project leader Peidong Yang, professor of chemistry and the S. K. and Angela Chan Distinguished Chair in Energy at UC Berkeley and director of the Kavli energy Nanoscience Institute said:
"On Mars, about 96% of the atmosphere is CO2. Basically, all you need is these silicon semiconductor nanowires to take in the solar energy and pass it on to these bugs to do the chemistry for you. For a deep space mission, you care about the payload weight, and biological systems have the advantage that they self-reproduce: You don't need to send a lot. That's why our biohybrid version is highly attractive."The only other requirement, besides sunlight, is water, which on Mars is relatively abundant in the polar ice caps and likely lies frozen underground over most of the planet.

Between 92 million and 83 million years ago, a diverse rainforest (shown in this artist's reconstruction) flourished within about 1,000 kilometers of the South Pole.
Buried sediment extracted from the seafloor off West Antarctica contains ancient pollen, fossilized roots and other chemical evidence of a diverse forest that flourished millions of years ago, less than a thousand kilometers from the South Pole.
The sediment offers the southernmost glimpse yet into just how warm Earth was during the mid-Cretaceous Period, between 92 million and 83 million years ago. By analyzing traces of vegetation in the sediment, researchers reconstructed climate conditions at the site. Average annual temperatures in the forest were about 13° Celsius, with summertime temperatures reaching as high as 20° or 25° C, the team reports in the April 2 Nature.
The mid-Cretaceous is known to have been one of the warmest periods on Earth in the last 140 million years, based on analyses of fossils and sediment collected from the seafloor closer to the equator. Atmospheric carbon dioxide levels are thought to have been at least 1,000 parts per million. (Today's atmospheric carbon dioxide levels average around 407 ppm, the highest in the last 800,000 years.)
Comment: As Pierre Lescaudron writes in Of Flash Frozen Mammoths and Cosmic Catastrophes there is strong evidence that our planet's geographic poles have shifted following cometary bombardment. In his article Did Earth 'Steal' Martian Water? we can see why dating in the region may not be particularly reliable.
This is further supported by other recent studies such as:
- Mysterious 25,000-year-old circular structure built from bones of 60 mammoths discovered in Russia's forest steppe
- Forgotten trove of fossil feathers belonged to tiny polar dinosaurs
- Volcanoes, Earthquakes And The 3,600 Year Comet Cycle
- Mammoth site is over 100,000 years older than previously thought - And the climate was warmer than it is today












Comment: Celestial Intentions: Comets and the Horns of Moses