Science News

. Voyager 1 talks balk
. The Verona astrolabe shows how science spreads
. How beetroot became red
. The life-saving impact of vaccines
Read more about some of these stories below.

. Voyager-1 talks back
When the writer of this article was still in school, the United States of America launched two interstellar probes, called Voyager 1 and Voyager 2, in 1977, nearly 50 years ago. It was a special moment in time. It was not just one of the early probes of space. It also took advantage of the fact that the two gas giants, Jupiter and Saturn, and the two ice giants, Uranus and Neptune, were positioned such that a single space-craft could fly by all of them.
As of 2024, the Voyagers are still in operation beyond the outer boundary of the heliosphere in interstellar space. They collect and transmit useful data to Earth. They are the most fascinating story of human beings' space enterprise. See the figure to understand the path they took to escape from Earth's gravity into space.
The Voyager primary mission was completed in 1989, with the close flyby of Neptune by Voyager 2. The Voyager Interstellar Mission (VIM) is a mission extension, which began when the two spacecraft had already been in flight for over 12 years. The VIM mission began when the two space-craft were distant more than 30 times the Sun-Earth distance!! 
The main objective of the VIM was to extend the exploration of the Solar System beyond the outer planets to the heliopause. This is the farthest extent at which the Sun's radiation dominates over interstellar winds. Beyond this point, the Sun exerts very little influence. The space-craft are truly outside the Solar system and deep in outer space.
Voyager 1 crossed the heliopause boundary in 2012, followed by Voyager 2 in 2018. Passing through the heliopause boundary has allowed both spacecraft to make measurements of the interstellar fields, particles and waves unaffected by the solar wind. The entire Voyager 2 scan platform, including all of the platform instruments, was switched off in 1998. All platform instruments on Voyager 1, except for the ultraviolet spectrometer (UVS) have also been switched off. The Voyager 1 scan platform was scheduled to go off-line in late 2000 but has been left on to investigate UV emission from the upwind direction.
The two spacecraft continue to operate, with some loss in subsystem redundancy but retain the capability to return scientific data from a full complement of Voyager Interstellar Mission (VIM) science instruments. Both spacecraft also have adequate electrical power and attitude control propellant to continue operating until around 2025. 
But why are they in the news? In December 2023, JPL, NASA, announced the problem was with one of Voyager 1's onboard computers called the flight data subsystem (FDS). Engineers attempted to restart the computer, but the problem persisted, NASA said. well, nobody should be surprised. When our phones and laptops have only a 5-year warranty, surely a 50-year life is more than expected.
But the NASA engineers did not give up. They found out the problem was a chip that was responsible for storing part of the computer's memory. It had become corrupted, making the data unreadable. The team was unable to repair the chip and decided the affected code needed to be stored elsewhere in the FDS memory, but no single location was large enough to do so.
The team devised a plan to divide the affected code into sections and store those sections in different places in the FDS. Just imagine the complexity of the task. The computer was on-board a space-craft 24 billion km from Earth (usually measured in AU units as 162.7 AU, where 1 AU is the Sun-Earth distance). It takes 22.5 hours for a radio signal to reach Voyager 1 and another 22.5 hours for the signal to come back to Earth. The engineers on Earth had not only to re-code the chip, but also move the code physically from one part of the chip to another unspoilt part. But they did it!
"Hi, it's me. - V1," the X (Twitter) account for Voyager 1 posted, to indicate this awesome success.
Over the next few weeks, more portions of the FDS software will be relocated and the team will work to enable the spacecraft to begin returning science data again, the JPL said.

. The Verona astrolabe shows how science spreads
Astrolabes were the world’s first smartphone, a portable computer which could be put to hundreds of uses. They provided a portable two-dimensional model of the universe fitting in their user’s hand, enabling them to calculate time, distances, plot the position of the stars and even forecast the future, by casting a horoscope.
Recently a 1000 year old 11th century Islamic astrolabe was found with both Arabic and Hebrew inscriptions. It was adapted, translated and corrected for centuries by Muslim, Jewish and Christian users in Spain, North Africa and Italy. How do we know this?
Dr Frederica Gigante from Cambridge’s History Faculty and Christ’s College, made the discoveries in a museum in Verona, Italy. It had not yet been studied in depth. She identified the object as Andalusian, and matched it to instruments made in Al-Andalus, the Muslim-ruled area of Spain, in the eleventh century. One side of a plate is inscribed in Arabic “for the latitude of Cordoba, 38° 30',” لعزض قرطبة لح ل, while the other side “for the latitude of Toledo, 40°,” لعزض طليطلة م . The astrolabe features Muslim prayer lines and prayer names, arranged to ensure that its original intended users kept to time to perform their daily prayers. 
It appears that it was later used by Jewish people. Hebrew inscriptions were added to the astrolabe by more than one hand. One of the Hebrew additions, engraved neatly above the Arabic marking for latitude 35°, reads “34 and a half” indicating that the astrolabe was now owned by people living at a lower latitude.
Dr Gigante said: “These Hebrew additions and translations suggest that at a certain point the object left Spain or North Africa and circulated amongst the Jewish diaspora community in Italy, where Arabic was not understood, and Hebrew was used instead.”
All sides of the astrolabe’s plates feature lightly scratched markings in Western numerals, translating and correcting the latitude values, some even multiple times. Dr Gigante thinks it is highly likely that these additions were made in Verona for a Latin or Italian language speaker.
The astrolabe is thought to have made its way into the collection of the Veronese nobleman Ludovico Moscardo (1611–81) before passing by marriage to the Miniscalchi family. In 1990, the family founded the Fondazione Museo Miniscalchi-Erizzo to preserve the collections.
“This object is Islamic, Jewish and European, they can’t be separated,” Dr Gigante said. How fascinating to imagine the different cultures and places that the astrolabe was in!

. How beetroot became red
Many plants, leaves and flowers are red in colour because they contain anthocyanins. Beets, it turns out, have evolved another, separate way of being red. Biologists recently reported that they have discovered a key step in the evolution of this process, which not only helps explain the origins of a brilliant natural color, but could have uses far beyond brightening your dinner table.
The pigments that give red beets their incandescent tint are called betalains. They’re made using an amino acid called tyrosine, which is the starting material for thousands of compounds made by plants. Plants modify tyrosine by adding other molecules to create an enormous array of useful substances. This is how morphine is made in the opium poppy, and mescaline in cactuses. Intrigued by this process, Hiroshi Maeda, a professor at University of Wisconsin, collaborated with beet experts to study how the plants make betalains from tyrosine.
Right away they found something peculiar. A tyrosine-making enzyme, which in most plants gets turned off after a certain amount is made, stays on longer in beets and some related species, producing an overload of the amino acid. This, it turns out, is likely the pivotal change that gave beets the starting material they would need to develop their special red.
At first, there would have been no use for the extra tyrosine. “The plants are freaked out: ‘What should I do with this?’” Dr. Maeda said. Eventually, however, some plants started to find a way to make something out of it.
At a later stage in their evolutionary history, red beets developed enzymes that use the extra tyrosine to create the rich scarlet we know so well. Scientists do not know exactly why this ability helped beets thrive. While some research suggests betalains may help plants weather stress, perhaps their primary usefulness is that humans — and presumably other creatures, like pollinators — love the way they look, Dr. Maeda said.
Beyond questions of color, the research has implications for medicine. While morphine is still produced in plantations of opium poppies, the discovery of an enzyme that increases the tyrosine used to make the pain-killing molecule could have effects on how that drug and others are made. The team is working to see whether they can boost tyrosine levels in other plants by giving them the enzyme found in beets.

. The life-saving impact of vaccines
An analysis of the impact of 50 years of the global vaccine programme shows the extraordinary value of vaccination. The world has become a much safer place to be a young child in the last 50 years. Since 1974, infant mortality worldwide has plummeted. In 1974, one in 10 newborns died before reaching their first birthday. By 2021, that rate had fallen by over two-thirds.
A lot of factors drove this change: lower poverty and better nutrition, cleaner air and water, and readily available antibiotics and other treatments. But one of the biggest contributors, a new study from the World Health Organization (WHO) concludes, was vaccines.
Vaccines alone, the researchers find, accounted for 40 percent of the decline in infant mortality. The paper — authored by a team of researchers led by World Health Organisation (WHO) epidemiologist and vaccine expert Naor Bar-Zeev — estimates that in the 50 years since 1974, vaccines prevented 154 million deaths. Of that 154 million, 146 million lives saved were among children under 5, including 101 million infants. Because the averted deaths were so concentrated among young people, who on average would go on to live for 66 years, vaccines gave their beneficiaries an astounding 9 billion additional years of life.
The paper was commissioned on the 50th anniversary of the WHO’s Programme on Immunization, which was launched in 1974. It was built on the success of the agency’s work in eradicating the killer disease smallpox. It covers a critical period of time. The previous decades had seen many important, newly developed vaccines: a joint diphtheria, pertussis, and tetanus vaccine in 1948, a polio vaccine in 1955, a measles vaccine in 1963. These were also available only in richer and developed countries.
Over the next 50 years, through vaccination campaigns led by the WHO and later Gavi (a multilateral group formerly called the Global Alliance for Vaccines and Immunization), this changed radically. In sub-Saharan Africa in 2021, 68 percent of 1-year-olds received a first dose of the measles vaccine, 78 percent received the tuberculosis vaccine, and 70–71 percent received the vaccines against hepatitis B, polio, and diphtheria/tetanus/pertussis. In India, the number of vaccinated children today stands at 76.1%, which means that a quarter of our children are still missing out.
This progress yielded massive gains, epecially the measles vaccine: it averted 93.7 million deaths from 1974 onward. In terms of lives saved, tetanus, pertussis, and tuberculosis are much smaller. Can you imagine that measles was such a killer? Today no-one is afraid of it.
The data is a reminder that vaccines have historically been one of our best tools for saving lives. Efforts to discover and distribute new ones for diseases like malaria and tuberculosis could have a similarly transformative effect.

Sources: NASA, University of Cambridge, New York Times, GAVI