Star swallows planet in first glimpse of Earth’s probable end:
Scientists said this week they have observed a dying star swallowing a planet for the first time, offering a preview of Earth’s expected fate in around five billion years.
But when the sun finally does engulf Earth, it will cause only a “tiny perturbation” compared to this cosmic explosion, the American astronomers said.
Most planets are believed to meet their end when their host star runs out of energy, turning into a red giant that massively expands, devouring anything unlucky enough to be in its path.
Astronomers had previously seen the before-and-after effects of this process, but had never caught a planet in the act of being consumed.
Kishalay De, a postdoctoral researcher at MIT in the US, and the lead author of the new study, said the accidental discovery unfolded like a “detective story”.
“It all started about three years ago when I was looking at data from the Zwicky Transient Facility survey, which takes images of the sky every night,” De said.
He stumbled across a star that had suddenly increased in brightness by more than 100 times over a 10-day period. The star is in the Milky Way galaxy, around 12?000 light years from Earth near the Aquila constellation, which resembles an eagle.
De had been searching for binary star systems, in which the larger star takes bites out of its companion, creating incredibly bright explosions called outbursts. But data showed that this outburst was surrounded by cold gas, suggesting it was not a binary star system.
And Nasa’s infrared space telescope Neowise showed dust had started to shoot out of the area months before the outburst.
More puzzling still was that the outburst produced about 1?000 times less energy than previously observed mergers between stars.
“You ask yourself, ‘What is 1?000 less massive than a star?’” De said.
The answer was close to home — Jupiter.
The team of researchers established that the swallowed planet was a gas giant with a similar mass to Jupiter but was so close to its star that it completed an orbit in just one day.
The star, which is similar to the sun, engulfed the planet over a period of around 100 days, starting by nibbling at its edges, which ejected dust. The bright explosion occurred in the final 10 days as the planet was totally destroyed when it plunged inside the star.
Miguel Montarges, an astronomer at the Paris Observatory who was not involved in the research, noted that the star was thousands of degrees hotter than the planet.
“It’s like putting an ice cube into a boiling pot,” he said.
Morgan MacLeod, a postdoc at Harvard University and co-author of the study, published in the journal Nature, said that most of the thousands of planets discovered outside the solar system so far “will eventually suffer this fate”.
In comparison, Earth will probably end not with a bang but a whimper. When the sun expands past Mercury, Venus and Earth in an estimated five billion years, they will make “less dramatic disturbances” because rocky planets are so much smaller than gas giants, MacLeod said.
“In fact, they will be really minor perturbations to the power output of the sun,” he said.
But even before it gets swallowed, Earth will already be “quite inhospitable” because the dying sun will have already evaporated all the planet’s water, MacLeod added.
Ryan Lau, astronomer and study co-author, said the discovery “speaks to the transience of our existence”.
“After the billions of years that span the lifetime of our solar system, our own end stages will likely conclude in a final flash that lasts only a few months,” he said.
Now that astronomers know what to look for, they hope that soon they will be able to watch many more planets be consumed by their stars.
In the Milky Way alone, a planet could be engulfed once a year, De said. — Agence France-Presse
Durban social housing battle goes to court:
Tenants in Durban blocks want the court to give them the right
to buy their homes
People are starving in South Africa, the land of plenty:
Foodies globally were left desolate this week with news of Jock Zonfrillo’s death. The chef and judge on MasterChef Australia inspired many with his kind words, and love for food and local cuisine.
As an avid watcher of MasterChef, I’ve developed an interest in food.
It sparked some thoughts about food and nutrition in South Africa.
In a country like ours, where there is such wealth, it is appalling that people go hungry. Everyone should have enough nutritious food. It is galling that the only meal that many children have each day is that provided by school feeding schemes.
In an ideal world, no one would go hungry. But we don’t live in an ideal world. Instead, it is one where, in 2021, about 2.1?million people experience hunger, according to Statistics South Africa.
My understanding of food security is when people have enough nutritious food.
Food insecurity was one of the reasons suggested for the July 2021 riots in KwaZulu-Natal and parts of Gauteng.
A previous Mail & Guardian article reported that South Africa is technically food secure but many households don’t have enough food for their dietary and nutritional needs.
The country “requires food accessibility, affordability, nutrition and stability over time”, said Wandile Sihlobo, chief economist at the Agricultural Business Chamber of South Africa.
The complication the country has is that our agricultural exports are doing well, generally, but people are malnourished and face food insecurity.
Stats SA also reported that there are more than half a million homes where children under the age of five experience hunger. Without adequate food that is nutritious, children are at risk of malnutrition, which can lead to stunting and physical and cognitive development problems. These children battle to learn and underperform at school, which perpetuates the cycle of poverty and struggle.
Irene Labuschagne, principal dietitian at the Nutrition Information Centre at Stellenbosch University, wrote that “one in 10 South Africans go hungry every day”.
Malnutrition is not only stunting, it can also lead to people being overweight and obese.
“The number of overweight children in South Africa has also grown. It increased from 10.6% in 2005 to 13.3% in 2016. This is more than twice the global prevalence of 5.6%,” she wrote.
The causes of malnutrition are many. There is a shift away from traditional diets to Western diets and lifestyles. People eat more unhealthy foods such as bad carbohydrates and excessive sugar and salt.
Fast foods are easily accessible, don’t have to be cooked and can be fairly cheap. Takeaway food is seen as sexy whereas greens and veggies aren’t.
But affordability is a key issue. Healthy food is expensive.
Jane Battersby, a researcher in urban food security, wrote, “The poor eat badly because it makes economic sense for them to do so. South Africa’s food system, for example, is one in which corporate power is concentrated. The system is dominated by ‘Big Food’ — large commercial entities that control the food market.”
What can be done?
Projects such as the national school feeding programme, which provides food to millions of children every day, must be supported.
Just as tobacco advertising is restricted, similar legislation must be introduced for unhealthy food and drinks. Sugar and salt taxes are a step in the right direction.
People need to be taught about healthy food choices and the government has a role to play in ensuring healthier food is accessible.
Battersby wrote: “Regulation of unhealthy foods without corresponding incentivisation of healthier foods is regressive. Likewise, if issues like access, storage, refrigeration and transport are not addressed, efforts to moderate food choice through pricing will only be an additional tax on the poor. It will not remedy food insecurity of either kind.”
Karen Hoffman and Safura Abdool Karim, of the University of the Witwatersrand, wrote that the environments people live in are behind their unhealthy food choices. Fast-food outlets and the high-calorie, high-sugar food they serve far outnumber grocery stores. Most poor areas have these fast-food shops whereas grocery stores can be found in wealthy areas.
Paddy Harper recently wrote in the M&G, “Millions of learners have struggled without the breakfast and lunch served as part of the national school nutrition programme since the Easter break because the company granted the tender either failed to deliver food or provided rotten food.”
The Special Investigating Unit is looking into corruption regarding the tender. Robbing children of healthy food is vile and those responsible must meet some harsh consequences.
Sheree Bega wrote in the M&G about how the Gauteng department of social development has reconfigured its R2.3?billion budget and that NGOs will lose funding, which will affect the people they care for — older people, children, people with disabilities.
For those of us who can afford it, let’s be part of a feeding scheme, let’s feed the needy, donate to charitable organisations or take food to an orphanage. Zonfrillo always closed off MasterChef by telling the contestants to be kind to yourselves and one another. We don’t know what battles other people are facing.
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