Friday, 5 January 2018

How I discovered the origins of the cigar-shaped alien 'asteroid' 'Oumuamua

File 20180102 26160 1fyd9h8.jpg?ixlib=rb 1.1
Artist’s illustration of planet formation. Image credit: NASA / Lynette Cook
Fabo Feng, University of Hertfordshire
One of the highlights of 2017 was the discovery of the first object in our solar system that definitely came from somewhere else. At first we thought it was a comet, then an asteroid, and now the International Astronomical Union has reclassified it as something new entirely, an interstellar object. The Hawaiian astronomers who discovered it aptly named it ‘Oumuamua, which means “a messenger from afar arriving first”, reflecting that this object is like a scout sent from the past to reach out to us.
Research has already helped us learn a lot about 'Oumuamua’s rare cigar-like shape, what it’s made of (ice with a carbon-rich surface) and its highly unusual orbit, which will take it out of our solar system at a speed of around 26 km/s. The Breakthrough Listen research program has even investigated whether 'Oumuamua is an alien space ship by scanning the object for life forms with the Green Bank Telescope. No intelligent signals have been identified so far, though further observations are planned.

Now my latest study gives us a glimpse of exactly where 'Oumuamua may have come from. Reconstructing the object’s motion, my research suggests it probably came from the nearby “Pleiades moving group” of young stars, also known as the “Local Association”. It was likely ejected from its home solar system and sent out to travel interstellar space.

'Oumuamua’s journey.

Based on 'Oumuamua’s trajectory, I simulated how it has probably travelled through the galaxy and compared this to the motions of nearby stars. I found the object passed 109 stars within a distance of 16 light years. It went by five of these stars from in the Local Association (a group of young stars likely to have formed together), at a very slow speed relative to their movement.
It’s likely that when 'Oumuamua was first ejected into space, it was travelling at just enough speed to break away from the gravity of its planet or star of origin, rather than at a much faster speed that would require even more energy. This means we’d expect the object to move relatively slowly at the start of its interstellar journey, and so its slow encounters with these five stars suggests it was ejected from one of the group.

When was it kicked out of its home?

Stars typically move with an average speed when they are formed and gradually change speed as they encounter very large objects, such as massive stars and molecular clouds and are affected by their gravity. Unlike most nearby stars, 'Oumuamua moves very slowly compared to the average motion of the rest of the galaxy. This suggests it has only been travelling in interstellar space for a relatively short time and hasn’t had a chance to encounter many massive objects that would speed it up.
We also have evidence for 'Oumuamua’s relatively young age from the colour of its surface. Outside of the protection of a star’s magnetic field, objects in space are bombarded with cosmic rays and interstellar dust and gas that gradually alter their surfaces and turn them very red in colour. But 'Oumuamua has a more neutral colour, suggesting it has only been impacted by cosmic rays for, at most, hundreds of million years rather than for the billions of years that our solar system has existed.

How was it ejected?

'Oumuamua is extremely elongated and has quite a different shape from other objects in our solar system. It was probably formed by a relatively high-energy process such as a collision, or ejected from a forming star. Most objects in the outer part of a planetary system are made more of ice and most objects in the inner regions are made more of rocks. Since 'Oumuamua is a more even mix of ice and rocks, it’s likely it came from the middle part of a solar system, similar to the asteroid belt between Mars and Jupiter that features a mixture of icy and rocky asteroids.

Young visitor. ESO/M. Kornmesser, CC BY-SA

Perhaps the most plausible scenario is that 'Oumuamua was ejected from a closely separated binary star system made of two stars closely orbiting each other. Objects orbiting one of the stars in a binary system will be strongly affected by the gravity of the other and so can be more easily ejected from the system than if it had just one star.

'Oumuamua is probably just the tip of the iceberg. My research suggests there are likely more than 46m similar interstellar objects crossing the solar system every year. Most of them will be too far away for us to see with our current telescopes. But new telescopes and surveys should soon be able to find these interstellar messengers, which may be sending us important information about how stars and planets formed. Studying more objects like 'Oumuamua will enable us to work out how much debris is left over from star formation and how much this adds to the mass of our galaxy.
The ConversationAnother reason to study these interstellar objects is that they could one day threaten to collide with the Earth and cause catastrophic events such as mass extinctions. The more we know, the better prepared we’ll be if that day ever comes.

Fabo Feng, Postdoctoral fellow, University of Hertfordshire
This article was originally published on The Conversation. Read the original article.

Thursday, 4 January 2018

Bullying isn't just verbal or physical – it can also be social, and this can have the worst effects

File 20171211 27683 ff15kf.jpg?ixlib=rb 1.1
Iakov Filimonov/
Kayleigh Chester, University of Hertfordshire
Bullying is a problem for schools worldwide. It is a fairly common behaviour, although it can be difficult to identify the number of young people who have been bullied because of the different ways bullying is measured. One 2014 review of 80 studies suggests that roughly 35% of children experience bullying at some point. In a class of 30 students, this would mean that ten young people will have been a victim of bullying. Childline reports that bullying is one of the top three reasons young people contact them.

Bullying is generally thought of as an intentional, harmful behaviour which is carried out repeatedly. The repetitive nature distinguishes bullying from other forms of conflict or aggression among young people. There are four main types of bullying behaviours: physical, verbal, cyber and relational (or social).

Relational bullying is probably the least known form of bullying. But it is also one of the most common forms, and can have more damaging effects than the other, better known forms of bullying. Relational bullying causes harm by destroying an individual’s peer relationships and social status. It could involve social exclusion: not inviting peers to take part in activities, for example, or spreading rumours and embarrassing information.

This type of bullying is sometimes called indirect, social or emotional bullying. While there may be subtle differences, overall it is accepted that they refer to the same types of bullying behaviour.

Bullying and health

Since the 1970s, when psychologist Dan Olweus first established the field of bullying research, much evidence has shown that bullying in schools can have very harmful effects.

The detrimental outcomes of bullying have been identified across the globe. Longitudinal research has demonstrated that these negative results can last into adulthood, with effects that include depression and anxiety. We often focus on the person who is being bullied, but research has also shown bullies are more likely to report negative outcomes in later life.

With the exception of cyberbullying, the different forms of bullying are often studied together. Cyberbullying emerged more recently, and has seen a lot of attention as researchers try to establish how it differs from the more traditional forms of bullying.

In my research, I focus exclusively on relational bullying. There has been very little research which has looked at relational bullying specifically, particularly in a UK context. There is often crossover between the four types of bullying, and studying bullying broadly can be helpful. But relational bullying warrants research attention as there is less awareness of and concern about this form of bullying.

My recently published findings, carried out with colleagues, highlight the damaging effects of relational bullying, above and beyond that of physical and verbal bullying. We analysed data collected from 5,335 young people aged 11, 13 and 15 through an anonymous survey completed during school lessons. The survey asked young people a number of questions about bullying, including relational bullying.

In particular, we wanted to see what kind of relationship there was between relational bullying and health-related quality of life, while also considering physical and verbal bullying. Health-related quality of life is a broader measure of a young person’s well-being which covers their physical, emotional, social and behavioural functioning. It fits with the broader World Health Organization definition of health, which states that health is not simply the absence of an illness.

We found that relational bullying is associated with lower health-related quality of life, and appears to have a larger influence than physical or verbal bullying – almost double that for verbal bullying. We also considered gender, and found the findings were the same for both boys and girls.

How to spot it

We have come a long way since bullying was viewed as just an unavoidable part of life, a rite of passage during your school years. We now have access to numerous charities aimed at providing support for those young people who are being bullied, for their parents, and advice for schools. There are a number of well-established, evidence-based interventions, and UK law specifies state schools must have anti-bullying policies in place. And these efforts aren’t in vain, with small decreases in bullying prevalence noted across 11 countries.

But are we thinking about relational bullying when we talk about anti-bullying? Teachers have demonstrated that they have less concern and are less likely to intervene in instances of relational bullying, while parents may not view social exclusion as bullying. Additionally, the UK government webpage does not include relational bullying behaviours in their definition.

The ConversationIt is important that school anti-bullying policies encompass relational bullying along with the more traditional forms of bullying. Yes, there is overlap between bullying behaviours, but it is essential that relational bullying is given as much attention as other forms. By its very nature, relational bullying can be difficult to identify. Raising awareness of what relational bullying is and how harmful it can be plays an important role in developing interventions for this behaviour.

Kayleigh Chester, PhD Candidate, University of Hertfordshire
This article was originally published on The Conversation. Read the original article.