Asteroid impact: NASA simulation shows we are sitting ducks - Big Think

Space agencies spot "near-Earth objects" (NEOs) all the time.

The NASA/JPL exercise made clear that six months is just not enough time with our current technology to prepare and launch a mission in time to nudge an NEO off its course.

The harrowing "tabletop exercise," as NASA/JPL called it, took place across four days at the conference:.

"Each time we participate in an exercise of this nature," says Johnson, "we learn more about who the key players are in a disaster event, and who needs to know what information, and when.".

An ancient skeleton of a man dating back to the Iron Age was uncovered outside of London last month, and though archaeologists aren't certain what the cause of death was, clues point to a murder most foul.

The ceremonial burial site included a circular ditch (about 60 feet across) at the center, and was a bit of a distance away from the ditch where the (suspected) murder victim was uncovered.

Similar Neolithic timber circles have been discovered around Great Britain, such as one near Stonehenge that is considered to date back to around the same time.

and Chinese team announced that it had successfully grown, for the first time, embryos that included both human and monkey cells.

On March 17, 2021, an Israeli team announced that it had grown mouse embryos for 11 days – about half of the gestation period – in artificial wombs that were essentially bottles.

Until this experiment, no one had grown a mammal embryo outside a womb this far into pregnancy.

and Chinese team announced that it had successfully grown, for the first time, embryos that included both human and monkey cells in plates to a stage where organs began to form.

However, ectogenesis could have far-reaching impacts on individuals and society, and the prospect of babies grown in a lab has not been put under nearly the same scrutiny as chimeras.

Mouse embryos were grown in an artificial womb for 11 days, and organs had begun to develop.

When in vitro fertilization first emerged in the late 1970s, the press called IVF embryos “test-tube babies," though they are nothing of the sort.

These embryos are implanted into the uterus within a day or two after doctors fertilize an egg in a petri dish.

Before the Israeli experiment, researchers had not been able to grow mouse embryos outside the womb for more than four days – providing the embryos with enough oxygen had been too hard.

This development is a major step toward ectogenesis, and scientists expect that it will be possible to extend mouse development further, possibly to full term outside the womb.

The Israeli team plans to deploy its techniques on human embryos.

Since mice and humans have similar developmental processes, it is likely that the team will succeed in growing human embryos in artificial wombs.

Once fetuses can be grown outside the womb, as in Huxley's world, researchers will also be able to modify their growing environments to further influence what physical and behavioral qualities these parentless babies exhibit.

Science still has a way to go before fetus development and births outside of a uterus become a reality, but researchers are getting closer.

If scientists can grow human cells in monkeys or other animals, it should be possible to grow human organs too.

But keeping human cells alive in the embryos of other animals for any length of time has proved to be extremely difficult.

In the human-monkey chimera experiment, a team of researchers implanted 25 human stem cells into embryos of crab-eating macaques – a type of monkey.

The researchers then grew these embryos for 20 days in petri dishes.

After 15 days, the human stem cells had disappeared from most of the embryos.

But at the end of the 20-day experiment, three embryos still contained human cells that had grown as part of the region of the embryo where they were embedded.

For scientists, the challenge now is to figure out how to maintain human cells in chimeric embryos for longer.

Their main concern is the ethical status of chimeras that contain human and nonhuman cells – especially if the human cells integrate into sensitive regions such as a monkey's brain.

Many ethicists are urging public discussion of appropriate regulation to determine how close to viability these embryos should be grown.

One proposed solution is to limit growth of these embryos to the first trimester of pregnancy.

Given that researchers don't plan to grow these embryos beyond the stage when they can harvest rudimentary organs, I don't believe chimeras are ethically problematic compared with the true test–tube babies of Huxley's world.

Few ethicists have broached the problems posed by the ability to use ectogenesis to engineer human beings to fit societal desires.

Researchers have yet to conduct experiments on human ectogenesis, and for now, scientists lack the techniques to bring the embryos to full term?

However, without regulation, I believe researchers are likely to try these techniques on human embryos – just as the now-infamous He Jiankui used CRISPR to edit human babies without properly assessing safety and desirability?

Technologically, it is a matter of time before mammal embryos can be brought to term outside the body.

But scientists and regulators would do well to reflect on the wisdom of permitting a process that could allow someone to engineer human beings without parents?

(Coincidentally, I was the speaker that followed Loeb the next week in the same seminar series and was cautioned — along with the other panelists — to behave myself to avoid another showdown. I smiled, knowing that my topic was pretty tame in comparison. I mean, how can the limits of human knowledge compare with alien surveillance?)